Video quality degradation from PS 19.1.9 to 20.0.6
When revisiting a video I had created in Photoshop previously, I re-exported an MP4 and saw noticeably worse quality. After searching possible causes and much trial and error, I downloaded an older version of Photoshop and tried exporting with the exact same settings. Same PSD file, same laptop - only difference in the Photoshop version. Result: original quality was restored. Did something happen to video quality between these two releases, or are there new settings I am unaware of that could negatively affect export quality?
Still frame from MP4 video exported with Photoshop 19.1.9:

Still frame from same video exported in Photoshop 20.0.6:

This is a very simple video - just two still images that alternate for 150ms each.