If the DescribableList is modified, transient actions need to be rebuilt.

core/src/main/java/hudson/model/AbstractProject.java

@@ -260,6 +260,12 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
         }
     }
 
+    @Override
+    public synchronized void save() throws IOException {
+        super.save();
+        updateTransientActions();
+    }
+
     @Override
     public void onCreatedFromScratch() {
         super.onCreatedFromScratch();