Also steam had long standing bug, when you move mouse with disabled their overlay. In about 20-30 minutes games were lagging. Elite was not affected, but root cause of that was input buffer overflow
A lot of details are already collected in: doitsujin/dxvk#4436 it could be related for a LD_PRELOAD added for the "record your game" feature? the workaround while we wait for the fix please see thi...
github.com
My favorite solution was to block that thing totally:
Some scripts, if you want to try. If you do, steam will try & fail self update on each run.
Lock / unlock update and restart Steam client.