Recently did an update from Ubuntu 16.04 to 18.04, which completely broke lirc which is the program that runs the IR remote.
So my unhappy partner was unable to use the remote in kodi until I finally worked out how to fix it (and every aspect of how they broke it).
Looks like they just changed the way it works for no useful reason. I had to manually set up every IR button again because the remote name had changed from "mce" to "devinput-32". Why??
MythTV didn't work at all because for some reason the mysql bind address had changed so it couldn't access its own database.
Once I got that working, I discovered that the remote didn't work in mythtv either. They had changed the name of the ?file? they use to send button names. I had to make a symbolic link to the new name so the remote would work in MythTV. "sudo ln -s /run/lirc/lircd /dev/lircd". Why??
Also I had a button set up on the IR remote to shutdown kodi. That stopped working and took me more time to fix.
Kodi was also throwing some python errors, fixed by doing "sudo apt install python-backports.functools-lru-cache"
The Kodi database also got corrupted somehow, so some files weren't showing up until I deleted the database, which meant I lost the resume times on videos we were watching. I spent a fair bit of time googling and trying to fix the database but in the end, no matter what I did those files would not show if the database was active on my movies folder.
Also the Nvidia drivers needed to be reinstalled, but I expected that because that breaks with every single update.
So yeah, that was about a week of evenings to get it working back the way it was.
Most of the other issues IIRC were annoyances more then anything else.
Every time I do an update on the Linux PC it always breaks a bunch of things and I typically have to spend 4-12 hours to fix everything.
But the good thing is that I can usually fix everything, and after it's fixed it will stay that way and work reliably for as long as I want until I choose to do another update.
I still love Linux, the only reason I'm using Windows at all is for certain software that doesn't work on Linux (Ableton and games, also no HDR support in Linux).