If after you hit attack, you see the invite screen for like 1/10th of a second and then it goes black except for your avatar on the left side, try these workarounds:
Take a screenshot, that makes it visible for me. I was doing a SS to send in for the big and noticed it fixed the problem - for that run only. Clearly not a fix, but it’s a workaround.
Tap madly in the center of the screen where the invite buttons n WOULD be.
drag down from upper right to show the control panel and tap to dismiss it. You get about 1 second to see the UI on the screen. You can click the buttons once the screen goes black, but seeing right where the buttons are can be helpful, especially in the avatar selection screen when you want to change to a non-animated avatar.
The bug does not occur on my iPad Air 3 running iOS 14.4.
My older Air2 was fine on the last 13.x version until I finally upgraded it to 14.4 today. I deleted and reinstalled the app, power cycled the iPad, etc, no luck in fixing the problem, but the two workarounds I mentioned work until PG can supply a fix.
It being able to invite means you cannot have anyone follow you for rad hits, war runs, atlas hits, invader runs for cpu for new baby dragons, etc.