I had to perform a Kernel and other updates (namely security updates to libraries). And as normal, the update manager listed all to be done and I followed suit with apply. There was the usual “Reboot Required” and all went fine. I had to shut down the computer that day and then I restarted it that evening and found my Plasma desktop was gone and in it’s place was the default Linux mint DE. I tried “sudo apt reinstall plasma”, no good and the same with “sudo apt install plasma”. I restored a previous save from TimeShift (days earlier) and the same updates appeared. This time I installed all the other updates first, then rebooted the machine followed by the Kernel update. All the update were applied and I still have my Plasma desktop. Like to know if anyone else had this experience?
I am just making assumptions here.
It is possible that the updates restore to default. Probably Plasma was already there but DE defaulted to Cinnamon. Did you check from the login screen if Plasma available?
While I not experienced in coding it my feeling that after having this problem happen before, I lost my print server because it was deleted with updated kernel.I know It sounds magical but I will continue to run all other updates BEFORE Updating the the kernel until I’m proven otherwise.