Oh boy, lots of a settings mess going on here. Whoever's advise you previously followed for OBS settings I'm about to discuss - I'd recommend ignoring them from now on.
And as noted above, I'll so far as to say I won't comment further if you insist on ignoring big read warning about not recording to MP4.
15:19:53.922: video settings reset:
15:19:53.922: base resolution: 1440x900
15:19:53.922: output resolution: 1440x900
15:19:53.922: downscale filter: Bilinear
15:19:53.922: fps: 120/1
15:19:53.922: format: NV12
15:19:53.922: YUV mode: sRGB/Full
recording at 120 fps with a 75HZ monitor? And for minecraft? what purpose are you trying to get with > 30fps?
Why did you change YUV mode? for now, put it back to default, and I suspect that will fix your issue