I’d like to add to that topic (since I can’t there anymore)- a good explanation from reddit user - Jackpkmn
“What’s happened here is that people are scrambling to get into a group as fast as possible. Put portal in the search and are repeatedly refreshing and applying as fast as they can to groups. If any group is not inviting but still listed they will report that group after a few seconds to remove it from their listing because this is the only way to remove a listing from your results screen in the base game.”