diff --git a/scripts/network/traefik/traefik_port_subdomains.sh b/scripts/network/traefik/traefik_port_subdomains.sh
index dd498eb..52fa315 100644
--- a/scripts/network/traefik/traefik_port_subdomains.sh
+++ b/scripts/network/traefik/traefik_port_subdomains.sh
@@ -38,10 +38,12 @@ tagsProcessorPortSubdomains()
 
         if [[ "$p_traefik" == "true" ]]; then
             local host
-            if [[ -z "$p_sub" || "$p_sub" == "@" || "$p_sub" == "root" ]]; then
-                host="${domain_full}"                 # apex / root of the domain
-            else
+            if [[ "$p_sub" == "@" || "$p_sub" == "root" ]]; then
+                host="${domain_full}"                 # apex / root of the domain (explicit only)
+            elif [[ -n "$p_sub" ]]; then
                 host="${p_sub}.${domain_full}"        # subdomain (single or multi-level)
+            else
+                host="${app_name}.${domain_full}"     # no subdomain set -> app-name default
             fi
             tagsManagerUpdateUniversalTag "$file" "DOMAINSUBNAME_TAG_${idx}" "$host"
         fi