I'm not using UC, I'm using IE and this happens on the Modern version and desktop. If you wish, I will install UC and try it.
It was always fine (for years) then suddenly I was on the mobile version. Then, as above, it was fixed for a few days but then reverted. Not only is a lot missing, in the mobile version, but it runs like a snail.
I spent quite some time last night on my 2520 in IE on WC. I used the developer panel to cycle through ALL the user agents and they are the same. Every one.
I'll need more time and more organization (not today, my plate is full with appointments and obligations) to repeat this and capture some debug data...
Then I will hopefully have something tech can use.