Steam will filter lobbies for you by your appid, but if there are more than your maximum requested results (50 in this case), you may not find the ones you’re looking for. UE4 session searches and Steam lobby searches support filtering of results based on key/values, but I am unsure how much of that is exposed through your AdvancedSessions plugin. You may want to add some unique game identifier to your sessions while you’re testing under the test app id, so you only get results you care about.