I have the same problem Claudio,
In the search bar it would not search any group I tried to search for 

I updated (after needing to update zap store)
and still had the same issue. 

I went to the desktop to login (to chachi), then join the group, now I'm in. But, in the video shown below👇, it still says in 0xchat I'm not in the group, but it is shown above that I joined earlier. 🤷‍♂️ seems like a 0xchat issue but idk
https://video.nostr.build/5a933e1293107dab3f32087f7796aa009cfc5d8f928f256cdad27aa687e9f9ec.mp4 

 I think the issue is caused by not fetching the group members list. You can try clicking “Join Group” or viewing the group information page on the top right button. It will fetch the group members list. 

 Thank you I'll try. Didn't want to confuse my relays with possibly the same npub