Since I started to use the UE 5.1 my server travels return Invalid URL only in packaged games.
The problem seems to be that UE 5.1 is only cooking the default game map, which is strange, because when I create the session I use open Level and its open any level, but when I use the server travel from the lobby to any selected map it returns the Invalid URL error. The problem disappears if I manually add all maps to the ‘List of maps to include in a packaged build’ in the Project Packaging Settings. The cooking/packaging time returns to “normal” (gets longer as usual) too.
Edit1: Setting the option ‘Cook everything in the project content directory (ignore list of maps below)’ to true seems to resolve the problem too.