The same thing happens to me, but I know the UI layout, so I can still click on things. However, everything is invisible. Also in-game some other UI also glitches such as the durability meter. I do not have the problem of joining random realms though. Also this may be different because i am on mobile.
The same thing happens to me, and i’m also on mobile. However there are more pressing issues than this. Mojang employees, if you are seeing this, please fix a bug that for going onto anything bout the main screen, it only shows the panorama. Basically UI won’t load anywhere.