My S20 ultra is performing excellent following April update. Camera performance is now exceptional along with battery life. I'm getting easy 8hrs screen on time using 120 refresh rate etc. This is while being on lock down and using for more often YouTube etc. I have compared S20 ultra camera to my Mrs iPhone 11 pro max and mates p40 pro the camera on S20 ultra now is equally as good as those if not better permitting now in some cases.
I'm having issues too after the April update. I almost think the April update made it worse. I took a pic yesterday of a nearly flat page; the center was nicely focused but an inch to either side was out of focus. I LOVE everything else about the phone, but I really wish they would fix the focus issues!
This, my friend, is not something that a software update will fix. It's not a bug or glitch. Look up "depth of field and sensor size". The camera on the Ultra may not be the best choice for this kind of photography, in will do great in many other situations though. Try moving your phone further from the subject and zooming in on it instead.
For me, latest update made photo quality worse. I have taken pictures with photo and pro mode and I noteced that in photo mode frame edges are softer and in pro mode they have just more noise and keep details. I had same effect with out of the box software and now this effect is back. S20 Ultra is worst samsung camera phone I have owned. Even my S9+ takes better photos in dim light.