Truly - I'm not trying to poke the bear with this comment! Well, okay - not too very much that is; so don't beat up too badly on me, ok?
Maybe much of the UC5 issues are related to the 12" screen. I have the "little brother" 8.4 screen in my 2022 2500. After the last software download (running version S21C.6), my system has been essentially rock solid. First thing I did after the updated downloaded was a factory reset. Since then, I can report the "glitchiness" has not resurfaced. The only complaint I can make is about the diesel prices showing up, or not. These are now there most of the time, but occasionally the fuel price will default to regular gas. Doing a soft reset solves that every time & the diesel prices return in short order. I do usually have to wait a few minutes for the info to populate, but the more I think about that, this is not unexpected. Where the heck does this info come from & how can my truck even know this? Gas station location info is one thing - to me that's pretty simple as part of a database as most gas stations don't move very often. But price info - and current prices at that - how is this info relayed to my truck????? If having - or not having- current fuel prices displayed on a screen in my dash is the worst complaint I can have about the UC5 in my truck, to me that's pretty insignificant, all things considered. Since I got my license in 1973, this is the first vehicle I've driven that even has such info.