Hm, I guess that's the preview? Maybe it doesn't take the aspect ratio changes into account.. See I view my finished mp4 files using Media Player Classic.

Also for reference, I use Hybrid version 2023.03.17.1

Hm. Yeah, I'm gonna go ahead and give the version you're using a shot, because right now I can't even export the new video file at all to see if it's just the preview that's stretched. Hybrid's just... sitting there, haha.

I also view the finished MP4 files in Media Player Classic, which has displayed them in the same horizontally-stretched way that Hybrid is showing it in the attached screenshot. :weird: