Video quality degrades when uploading to YouTube with variable frame rate
Not sure why YouTube would be degrading the video quality because of the lower framerate. Perhaps, after recording at the lower framerate, re-encode the videos using 60fps before uploading. It'll make the file bigger without the actual benefit of the higher framerate (just creates duplicate frames), but maybe worth it if it prevents video quality from degrading.

Edit: OBS uses FFmpeg, &amp; FFmpeg has some recommended settings specific for YouTube. If you are using the same settings for both videos, this is probably irrelevant.