Immediately after the update that renames KDE and plasma packages with a 5 at the end of their name, KDE and plasma start to have a memory leak. The system becomes unresponsive. I reboot and can see the login page.
When I log in, it freezes on the plasma framework splash screen and then turns black. Switching over to tty3, I’m able to timeshift back to a safe snapshot before the update. But I can’t seem to update the system.
6.1.63 is currently the latest lts. So you might want to update again as you are several weeks behind on updates - chances are your issue is already gone again.
You might want to refresh your mirror list first to solve your update issue and after you have to say yes to all replace - questions during the update.
you might want to switch to breeze - icons before doing the update, could also be an incomaptible icon pack.
That being said, I have not noticed any memory leak in KDE for the last weeks, currently I have 10 hours uptime and RAM usage is completely normal.