Typically about half my applications stop working, they crash on launch. Or sometimes the machine won't even finish booting -- I'll get past the decryption password entry, it'll mount some things and then spew a thousand lines of "BPF: Invalid name" error messages and just stop there. I found if I hit Enter that I was sitting at a prompt, already logged in, but couldn't figure out what to do from there.

However, I'm an old DOS nerd so mashing keys on boot is one of the first things I try. Pop has a bootloader that let me revert to the previous something, I guess that's an older kernel? And that loaded right up and got me into the GUI and all my apps worked and everything. So from there I found the "incomplete upgrade" support page, ran those commands, and rebooted again and tried the newer kernel again, and it came right up, all fixed.

The first noticeable breakage was settings for VINO (vnc server) got reset and vnc was my only way to remote desktop in. I had to hook up a monitor, mouse, and keyboard to fix this. It also broke python somehow (I can't remember exactly what happened here) and caused a bunch of my build scripts to break. Fix was to re-install python3 and set alternatives.