Same issue here - ever since the 1.1.5 update. Works fine on my iPad pro, but my iPad 2 fails constantly. It was working fine before the update.
Also since the update I can't accept any realm invites. The checkmark button doesn't do anything.
I tried deleting and reinstalling the app and it still fails.
Yes, I forgot to add that detail. When I finally am able to reconnect to the realm, the banner is back on the wall.