Basic education (should) covers scientific method and an understanding that a similar (but common) symptom, doesn't indicate causation
And your description does NOT indicate it is something with OBS. at all. for multiple reasons
1. you aren't even running OBS Studio? but instead a forked version from a company known for even worse s/w code quality?
2. PEBKAC /id10t related - someone indicating surprise to learn that running 2 very demanding workloads simultaneously might have a performance impact - which is NOT a real 'problem' just a reasonably foreseeable reality...
oh, and blaming 1 of the demanding workloads vs the other... just silly
As for change/updates and troubleshooting, In general, Many users fail to account for OS and h/w driver updates, such that there are multiple changes that happen, not just OBS. And Win10 updates have NOT been know for their quality. If in your case, if the issue is a specific update (example OBS Studio v27 or v27.0.1)... then doing a bug report is appropriate, not commenting on a 6+ month old thread which was NOT about OBS v27. Or might it be related to the MS KB being released this week in regards to gaming performance?
At times I've had more free time, but if I'm busy, with my volunteer time I will be brief to point people in the right direction. Whining will get at best an annoyed reaction from me. I'll now unwatch/ ignore this thread