diff --git a/ansible/roles/podman/templates/zomboid/install.scmd.j2 b/ansible/roles/podman/templates/zomboid/install.scmd.j2
index 9acf740..499ff4f 100644
--- a/ansible/roles/podman/templates/zomboid/install.scmd.j2
+++ b/ansible/roles/podman/templates/zomboid/install.scmd.j2
@@ -13,7 +13,13 @@ force_install_dir /project-zomboid
 login anonymous
 
 // Install/Update the Project Zomboid Dedicated Server (Build 42, stable)
-// No -beta: B42 became the default branch at 42.20.
-app_update 380870 validate
+//
+// -beta public is required, not optional. Dropping the flag entirely does NOT
+// leave a previously-selected beta: SteamCMD writes the new branch to the
+// manifest's UserConfig but leaves MountedConfig -- and the actual installed
+// content -- on the old one. That failed silently here, leaving the server on
+// the 42.14.1 unstable build while the config had already moved to the mod-ID
+// syntax that only 42.20+ accepts, so every mod reported "not found".
+app_update 380870 -beta public validate
 
 quit