diff --git a/vm/archlinux-vm.sh b/vm/archlinux-vm.sh
index 482f09c85..cbd966c8b 100644
--- a/vm/archlinux-vm.sh
+++ b/vm/archlinux-vm.sh
@@ -310,7 +310,10 @@ function advanced_settings() {
       HN="arch-linux"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo "${VM_NAME,,}" | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/debian-13-vm.sh b/vm/debian-13-vm.sh
index 4b52b7d47..e0493a81e 100644
--- a/vm/debian-13-vm.sh
+++ b/vm/debian-13-vm.sh
@@ -325,7 +325,10 @@ function advanced_settings() {
       HN="debian"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo "${VM_NAME,,}" | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/debian-vm.sh b/vm/debian-vm.sh
index cff40a43a..6081ebc83 100644
--- a/vm/debian-vm.sh
+++ b/vm/debian-vm.sh
@@ -315,7 +315,10 @@ function advanced_settings() {
       HN="debian"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/docker-vm.sh b/vm/docker-vm.sh
index 42fb22091..45adb5608 100644
--- a/vm/docker-vm.sh
+++ b/vm/docker-vm.sh
@@ -251,7 +251,10 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       HN="docker"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
   else
diff --git a/vm/haos-vm.sh b/vm/haos-vm.sh
index 832640e0a..bed97a588 100644
--- a/vm/haos-vm.sh
+++ b/vm/haos-vm.sh
@@ -391,7 +391,10 @@ function advanced_settings() {
       HN="haos${BRANCH}"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/mikrotik-routeros.sh b/vm/mikrotik-routeros.sh
index 4e46f5900..0b383e8c1 100644
--- a/vm/mikrotik-routeros.sh
+++ b/vm/mikrotik-routeros.sh
@@ -377,7 +377,10 @@ function advanced_settings() {
       HN="mikrotik-routeros-chr"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/nextcloud-vm.sh b/vm/nextcloud-vm.sh
index 3307cc6b7..460e4f07f 100644
--- a/vm/nextcloud-vm.sh
+++ b/vm/nextcloud-vm.sh
@@ -313,7 +313,10 @@ function advanced_settings() {
       HN="nextcloud-vm"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/openwrt-vm.sh b/vm/openwrt-vm.sh
index c7e030245..4260a3be6 100644
--- a/vm/openwrt-vm.sh
+++ b/vm/openwrt-vm.sh
@@ -328,7 +328,10 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       HN="openwrt"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
diff --git a/vm/opnsense-vm.sh b/vm/opnsense-vm.sh
index 71ec65f41..243f02108 100644
--- a/vm/opnsense-vm.sh
+++ b/vm/opnsense-vm.sh
@@ -421,7 +421,10 @@ function advanced_settings() {
     if [ -z "$VM_NAME" ]; then
       HN="OPNsense"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
     fi
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
diff --git a/vm/owncloud-vm.sh b/vm/owncloud-vm.sh
index d0ebe2115..7738ecbb8 100644
--- a/vm/owncloud-vm.sh
+++ b/vm/owncloud-vm.sh
@@ -314,7 +314,10 @@ function advanced_settings() {
       HN="owncloud-vm"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/pimox-haos-vm.sh b/vm/pimox-haos-vm.sh
index a3bbba24d..708be777f 100644
--- a/vm/pimox-haos-vm.sh
+++ b/vm/pimox-haos-vm.sh
@@ -274,7 +274,10 @@ function advanced_settings() {
     echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
   else
     if [ $exitstatus = 0 ]; then
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${DGN}Using Hostname: ${BGN}$HN${CL}"
     fi
   fi
diff --git a/vm/truenas-vm.sh b/vm/truenas-vm.sh
index 3e7274543..1386d0783 100644
--- a/vm/truenas-vm.sh
+++ b/vm/truenas-vm.sh
@@ -355,7 +355,10 @@ function advanced_settings() {
     if [ -z $VM_NAME ]; then
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/ubuntu2204-vm.sh b/vm/ubuntu2204-vm.sh
index 0c281ec7f..9f4b0ac13 100644
--- a/vm/ubuntu2204-vm.sh
+++ b/vm/ubuntu2204-vm.sh
@@ -310,7 +310,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/ubuntu2404-vm.sh b/vm/ubuntu2404-vm.sh
index eba9846a5..283986b24 100644
--- a/vm/ubuntu2404-vm.sh
+++ b/vm/ubuntu2404-vm.sh
@@ -313,7 +313,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/ubuntu2504-vm.sh b/vm/ubuntu2504-vm.sh
index f9040855d..2ec9e65d8 100644
--- a/vm/ubuntu2504-vm.sh
+++ b/vm/ubuntu2504-vm.sh
@@ -312,7 +312,10 @@ function advanced_settings() {
       HN="ubuntu"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else
diff --git a/vm/umbrel-os-vm.sh b/vm/umbrel-os-vm.sh
index fc193d0bb..1fc47c825 100644
--- a/vm/umbrel-os-vm.sh
+++ b/vm/umbrel-os-vm.sh
@@ -373,7 +373,10 @@ function advanced_settings() {
       HN="umbrelos"
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     else
-      HN=$(echo ${VM_NAME,,} | tr -d ' ')
+      HN=$(echo "${VM_NAME,,}" | tr -cs 'a-z0-9-' '-' | sed 's/^-//;s/-$//')
+      if [ "$HN" != "${VM_NAME,,}" ]; then
+        whiptail --backtitle "Proxmox VE Helper Scripts" --title "HOSTNAME ADJUSTED" --msgbox "Invalid characters detected. Hostname has been adjusted to:\n\n  $HN" 10 58
+      fi
       echo -e "${HOSTNAME}${BOLD}${DGN}Hostname: ${BGN}$HN${CL}"
     fi
   else