Question does the system work with windows?
you could have a defect controller or a defect nvme.
I bought a new laptop some years ago, I suspected the nvme to be defect, did a waranty claim, received the nvme and realized the controller was actually corrupted.
is this a notebook? Do you have a second nvme slot on the board?
Hi there,
I looked a little bit into the problem. I found an issue. baloo_file is continously writing (do not know why not reading) to the disk with ~300 M/s (see iotop output).
This could be the main reason for the issue. Thanks a lot!
I will keep you updated.
I think some users disable that baloo serviceā¦ Iām not a Plasma userā¦
Omg thatās some big numbers writing, just disable baloo and kde search and its components in general in the kde control center, they seems to cause issues. That were my observations while trialing plasma desktop.
At the moment I just killed the process and deleted the data base.
Now, the ābugā is gone.
If it will appear again, I will deactivate indexing.
For the last 4hrs I had no freeze. So hopefully this was the issue an it is solved.
Will update if it is finally gone. Thanks a lot for the help 
Update: Problem seems to be solved now.
baloo service was the issue. Thanks all!
