Turn off Windows Game DVR.
The log shows no real stutter-problem within the encoding/rendering, so maybe it's just a local problem on your side...for example the usage of multiple monitors with mismatching refreshrates.
Do you have more than one monitor? If so, are they running at the same refreshrate?
Windows is not working well with mixed refreshrates, as soon, as both monitors are showing any GPU accelerated content (video in browser or OBS preview for example).
edit:
Why are you using window_capture instead of game_capture? This can cause big performance problems (as well es having monitor_capture and window_capture in the same scene, which makes not much sense)