Today I noticed a problem in my desktop computer, after this update. Plasma 6.4.3. Whenever I sent a file to my Android phone using KDE Connect, plasmashell crashed. Plasmashell restarted immediately after that (and an automatic report of the crashing was sent to KDE), and curiously, the file was always successfully received in my phone, that never failed.
I did a search, and found this message on the Manjaro forum
Please check if you are running some incompatible settings from a theme, a plasmoid - anything that is not updated to latest Plasma release.
https://forum.manjaro.org/t/plasmashell-6-4-0-crashes/179016/7
That was it. I changed the theme from Solus Dark to Breeze Dark, sent a few files to my phone, and plasmashell did not crash.
Does anyone who uses Solus Plasma, and a different theme from Breeze, have the same problem?
EDIT: I had plasmashell crush again while sending a file, in Breeze dark. So not solved. I changed the theme back to Solus Dark, reinstalled KDE Connect, sent a few files to my phone, and plasmashell did not crash. Now I can't reboot my computer, when possible, I will reboot again, and check if plasmashell crashes or not.
EDIT 2: More info. Plasmashell crashes only when I enter Notifications. Otherwise, it doesn't crash. It also crashes when moving files from one disk to another one, if I enter notifications. In any case, files always get successfully moved, or sent to my phone, so this is more of an annoyance than a real problem.