@[deleted]
Okay, so you're absolutely right about the funky MKV file. I tried a MP4 and an AVI video, both of them worked just fine. My best guess is an OBS update which was released 4 days ago and most likely messed up my recordings. I will install the OBS version I had before that, and that will hopefully fix it.
I have 4 more funky MKV videos, but converting them as a whole to an AVI (I prefer AVI over MP4) format and then editing those files in videopad seems to do the trick.
Thanks for your help! 😊