I’ve posted this before, but will repeat in case anyone hasn’t seen it......
Support talked me through deleting and reinstalling the app, and it worked - for just 24hours! Then it got stuck again
Following advice from someone on here (thanks!) I installed the Gmail app (which can be used for other email providers too) and not only does that work fine, but it seemed to clear a blockage in the apple app, so now that is working ok too.
If it gets sluggish, I use the gmail one, but mostly I use apple
Hope that helps anyone who is struggling, but I completely agree - this is Apple’s problem, and it’s unacceptable that they haven’t fixed it