Weird error with webinar recording

Hi, I am having trouble properly converting a  webinar I recorded to mp4. The webinar included presentations where co-hosts shared their screens. However, at one point early in the recording, the presentations freeze, and the image on the main 'tile' remains frozen on that slide for the rest of the recording. Even though the slides changed every minute or so during the actual meeting. I've tried converting the .zoom output file multiple times now.

In the recording, the tile(s) showing participants' webcams in the top right corner converts fine and does not freeze, you can see people moving etc on their cameras.

The audio converts fine all the way through.

Does anyone know why just the presentation tile froze in the recording, and is there any way to fix this?

Thanks,

Len