Try the following:
- In your X session, notice the [nvidia] kernel thread.
- Log off your X session and stop your display manager. No more Xorg instances should be currently running.
- Notice the [nvidia] kernel thread correctly disappeared.
- systemctl hibernate and resume. Notice a new [nvidia] kernel thread.
Now try one of two things:
A) Either rmmod nvidia-uvm nvidia-drm nvidia-modeset nvidia and notice the stale [nvidia] kernel thread from step 4 is still there.
B) Or start a new x session and notice two [nvidia] kernel threads.
Screenshot showing multiple nvidia kernel threads: