diff --git a/misc/build.func b/misc/build.func
index 12eebc96..3d3ba3a6 100644
--- a/misc/build.func
+++ b/misc/build.func
@@ -4604,48 +4604,73 @@ EOF'
       msg_warn "apt-get update failed, trying alternate mirrors..."
       pct exec "$CTID" -- bash -c '
         APT_BASE="sudo curl mc gnupg2 jq"
-        MIRRORS="
-          ftp.debian.org
-          ftp.us.debian.org
-          ftp.de.debian.org
-          ftp.fr.debian.org
-          ftp.nl.debian.org
-          ftp.uk.debian.org
-          ftp.ch.debian.org
-          ftp.se.debian.org
-          ftp.it.debian.org
-          ftp.au.debian.org
-          ftp.jp.debian.org
-          ftp.ca.debian.org
-          debian.csail.mit.edu
-          mirrors.ocf.berkeley.edu
-          mirrors.wikimedia.org
-          debian.osuosl.org
-          mirror.cogentco.com
-          ftp.fau.de
-          ftp.halifax.rwth-aachen.de
-          debian.mirror.lrz.de
-          mirror.init7.net
-          debian.ethz.ch
-          mirrors.dotsrc.org
-          debian.mirrors.ovh.net
-          mirror.aarnet.edu.au
-        "
+        EU_MIRRORS="ftp.de.debian.org ftp.fr.debian.org ftp.nl.debian.org ftp.uk.debian.org ftp.ch.debian.org ftp.se.debian.org ftp.it.debian.org ftp.fau.de ftp.halifax.rwth-aachen.de debian.mirror.lrz.de mirror.init7.net debian.ethz.ch mirrors.dotsrc.org debian.mirrors.ovh.net"
+        US_MIRRORS="ftp.us.debian.org ftp.ca.debian.org debian.csail.mit.edu mirrors.ocf.berkeley.edu mirrors.wikimedia.org debian.osuosl.org mirror.cogentco.com"
+        AP_MIRRORS="ftp.au.debian.org ftp.jp.debian.org ftp.tw.debian.org ftp.kr.debian.org ftp.in.debian.org ftp.hk.debian.org ftp.sg.debian.org mirror.aarnet.edu.au mirror.nitc.ac.in"
+
+        TZ=$(cat /etc/timezone 2>/dev/null || echo "UTC")
+        case "$TZ" in
+          Europe/*|Arctic/*) REGIONAL="$EU_MIRRORS"; OTHERS="$US_MIRRORS $AP_MIRRORS" ;;
+          America/*) REGIONAL="$US_MIRRORS"; OTHERS="$EU_MIRRORS $AP_MIRRORS" ;;
+          Asia/*|Australia/*|Pacific/*) REGIONAL="$AP_MIRRORS"; OTHERS="$EU_MIRRORS $US_MIRRORS" ;;
+          *) REGIONAL=""; OTHERS="$EU_MIRRORS $US_MIRRORS $AP_MIRRORS" ;;
+        esac
+        MIRRORS="$(printf "%s\n" $REGIONAL | shuf) ftp.debian.org $(printf "%s\n" $OTHERS | shuf)"
+
         echo "Acquire::By-Hash \"no\";" >/etc/apt/apt.conf.d/99no-by-hash
+        FAIL_COUNT=0
         for mirror in $MIRRORS; do
+          timeout 2 bash -c "echo >/dev/tcp/$mirror/80" 2>/dev/null || { echo "  [skip] $mirror (unreachable)"; continue; }
+          echo "  [try] $mirror ..."
           for src in /etc/apt/sources.list.d/debian.sources /etc/apt/sources.list; do
             [ -f "$src" ] && sed -i "s|URIs: http[s]*://[^/]*/|URIs: https://${mirror}/|g; s|deb http[s]*://[^/]*/|deb https://${mirror}/|g" "$src"
           done
           rm -rf /var/lib/apt/lists/*
-          if apt-get update >/dev/null 2>&1 && apt-get install -y $APT_BASE >/dev/null 2>&1; then
+          APT_OUT=$(apt-get update 2>&1)
+          if echo "$APT_OUT" | grep -qi "hashsum\|hash sum"; then
+            echo "  [fail] $mirror (hash mismatch)"
+            echo "$APT_OUT" | grep -i "hash" | head -3 | sed "s/^/         /"
+          elif apt-get install -y $APT_BASE >/dev/null 2>&1; then
+            echo "  [ok] $mirror"
             exit 0
+          else
+            echo "  [fail] $mirror"
           fi
+          FAIL_COUNT=$((FAIL_COUNT + 1))
+          [ "$FAIL_COUNT" -ge 3 ] && exit 2
         done
         exit 1
-      ' || {
+      '
+      mirror_exit=$?
+      if [[ $mirror_exit -eq 2 ]]; then
+        msg_warn "Multiple mirrors failed (possible CDN synchronization issue)."
+        msg_info "Find Debian mirrors at: https://www.debian.org/mirror/list"
+        local custom_mirror=""
+        while true; do
+          read -rp "  Enter a Debian mirror hostname (or 'skip' to abort): " custom_mirror </dev/tty
+          [[ -z "$custom_mirror" ]] && continue
+          [[ "$custom_mirror" == "skip" ]] && break
+          [[ ! "$custom_mirror" =~ ^[a-zA-Z0-9._-]+$ ]] && {
+            msg_warn "Invalid hostname format."
+            continue
+          }
+          pct exec "$CTID" -- bash -c "
+            for src in /etc/apt/sources.list.d/debian.sources /etc/apt/sources.list; do
+              [ -f \"\$src\" ] && sed -i \"s|URIs: http[s]*://[^/]*/|URIs: https://${custom_mirror}/|g; s|deb http[s]*://[^/]*/|deb https://${custom_mirror}/|g\" \"\$src\"
+            done
+            rm -rf /var/lib/apt/lists/*
+            apt-get update >/dev/null 2>&1 && apt-get install -y sudo curl mc gnupg2 jq >/dev/null 2>&1
+          " && break
+          msg_warn "Mirror '${custom_mirror}' also failed. Try another or type 'skip'."
+        done
+        if [[ "$custom_mirror" == "skip" ]]; then
+          msg_error "apt-get base packages installation failed"
+          exit 1
+        fi
+      elif [[ $mirror_exit -ne 0 ]]; then
         msg_error "apt-get base packages installation failed"
         exit 1
-      }
+      fi
     }
   fi
 
diff --git a/misc/install.func b/misc/install.func
index cc395211..bfb149ec 100644
--- a/misc/install.func
+++ b/misc/install.func
@@ -202,44 +202,82 @@ pkg_update() {
   apt)
     if ! $STD apt-get update; then
       msg_warn "apt-get update failed, trying alternate mirrors..."
-      local mirrors="
-        ftp.debian.org
-        ftp.us.debian.org
-        ftp.de.debian.org
-        ftp.fr.debian.org
-        ftp.nl.debian.org
-        ftp.uk.debian.org
-        ftp.ch.debian.org
-        ftp.se.debian.org
-        ftp.it.debian.org
-        ftp.au.debian.org
-        ftp.jp.debian.org
-        ftp.ca.debian.org
-        debian.csail.mit.edu
-        mirrors.ocf.berkeley.edu
-        mirrors.wikimedia.org
-        debian.osuosl.org
-        mirror.cogentco.com
-        ftp.fau.de
-        ftp.halifax.rwth-aachen.de
-        debian.mirror.lrz.de
-        mirror.init7.net
-        debian.ethz.ch
-        mirrors.dotsrc.org
-        debian.mirrors.ovh.net
-        mirror.aarnet.edu.au
-      "
+      local eu_mirrors="ftp.de.debian.org ftp.fr.debian.org ftp.nl.debian.org ftp.uk.debian.org ftp.ch.debian.org ftp.se.debian.org ftp.it.debian.org ftp.fau.de ftp.halifax.rwth-aachen.de debian.mirror.lrz.de mirror.init7.net debian.ethz.ch mirrors.dotsrc.org debian.mirrors.ovh.net"
+      local us_mirrors="ftp.us.debian.org ftp.ca.debian.org debian.csail.mit.edu mirrors.ocf.berkeley.edu mirrors.wikimedia.org debian.osuosl.org mirror.cogentco.com"
+      local ap_mirrors="ftp.au.debian.org ftp.jp.debian.org ftp.tw.debian.org ftp.kr.debian.org ftp.in.debian.org ftp.hk.debian.org ftp.sg.debian.org mirror.aarnet.edu.au mirror.nitc.ac.in"
+
+      local tz regional others
+      tz=$(cat /etc/timezone 2>/dev/null || echo "UTC")
+      case "$tz" in
+      Europe/* | Arctic/*)
+        regional="$eu_mirrors"
+        others="$us_mirrors $ap_mirrors"
+        ;;
+      America/*)
+        regional="$us_mirrors"
+        others="$eu_mirrors $ap_mirrors"
+        ;;
+      Asia/* | Australia/* | Pacific/*)
+        regional="$ap_mirrors"
+        others="$eu_mirrors $us_mirrors"
+        ;;
+      *)
+        regional=""
+        others="$eu_mirrors $us_mirrors $ap_mirrors"
+        ;;
+      esac
+      local mirrors
+      mirrors="$(printf '%s\n' $regional | shuf) ftp.debian.org $(printf '%s\n' $others | shuf)"
+
       echo 'Acquire::By-Hash "no";' >/etc/apt/apt.conf.d/99no-by-hash
       local apt_ok=false
+      local fail_count=0
       for mirror in $mirrors; do
+        timeout 2 bash -c "echo >/dev/tcp/$mirror/80" 2>/dev/null || {
+          msg_info "Mirror skip: ${mirror} (unreachable)"
+          continue
+        }
+        msg_info "Trying mirror: ${mirror}"
         for src in /etc/apt/sources.list.d/debian.sources /etc/apt/sources.list; do
           [[ -f "$src" ]] && sed -i "s|URIs: http[s]*://[^/]*/|URIs: https://${mirror}/|g; s|deb http[s]*://[^/]*/|deb https://${mirror}/|g" "$src"
         done
         rm -rf /var/lib/apt/lists/*
-        if $STD apt-get update; then
+        local apt_out
+        apt_out=$(apt-get update 2>&1)
+        if echo "$apt_out" | grep -qi "hashsum\|hash sum"; then
+          msg_warn "Mirror failed: ${mirror} (hash mismatch)"
+          echo "$apt_out" | grep -i "hash" | head -3 | sed 's/^/         /'
+        elif echo "$apt_out" | grep -q "^E:"; then
+          msg_warn "Mirror failed: ${mirror}"
+        else
+          msg_ok "Using mirror: ${mirror}"
           apt_ok=true
           break
         fi
+        fail_count=$((fail_count + 1))
+        if [[ $fail_count -ge 3 ]]; then
+          msg_warn "Multiple mirrors failed (possible CDN synchronization issue)."
+          msg_info "Find Debian mirrors at: https://www.debian.org/mirror/list"
+          while true; do
+            read -rp "  Enter a Debian mirror hostname (or 'skip' to abort): " custom_mirror </dev/tty
+            [[ -z "$custom_mirror" ]] && continue
+            [[ "$custom_mirror" == "skip" ]] && break
+            [[ ! "$custom_mirror" =~ ^[a-zA-Z0-9._-]+$ ]] && {
+              msg_warn "Invalid hostname format."
+              continue
+            }
+            for src in /etc/apt/sources.list.d/debian.sources /etc/apt/sources.list; do
+              [[ -f "$src" ]] && sed -i "s|URIs: http[s]*://[^/]*/|URIs: https://${custom_mirror}/|g; s|deb http[s]*://[^/]*/|deb https://${custom_mirror}/|g" "$src"
+            done
+            rm -rf /var/lib/apt/lists/*
+            if $STD apt-get update; then
+              apt_ok=true
+              break 2
+            fi
+            msg_warn "Mirror '${custom_mirror}' also failed. Try another or type 'skip'."
+          done
+          break
+        fi
       done
       if [[ "$apt_ok" != true ]]; then
         msg_error "All mirrors failed. Check network or try again later."