I chose the production preset to edit more smoothly but scrubbing through it's 99% black in the preview window. Disabling GPU processing doesn't work (though even if it did, that probably wouldn't help since my goal is to transcode footage to edit more smoothly). I reset Vegas Pro and deleted cached data, which also didn't work. Afterwards, I re-enabled the deprecated features "Allow legacy GPU rendering" and "Enable the Quicktime plugin", which also didn't solve the issue. I've had the K-lite Codec Pack and x264vfw installed as well. Sometimes me alt-tabbing, waiting, and alt-tabbing back will just make it start previewing correctly for a few seconds in seemingly random parts of the video. I think it's fair to say it's definitely not a corrupted video issue, as the videos play back perfectly fine using any video player I've attempted it on and this editing issue has occurred on both occasions where I transcoded videos using the production preset.
Here's some info on one of the videos being used. I'd really like to get this to work because handbrake is fast and it will be annoying to get some videos transcoded if I can't use handbrake to do it
Software & Specs: VP20.0 Build 214/5800x/32GB RAM/3070 Ti/Fast SSDs