Exporting videos imported in from another editing software is making the audio glitch

So I use another editing software apart from Premiere for some social media edits. Yesterday I exported a short sequence from that software (made it a point to check that all the settings matched the original footage) and brought it into Premiere as a ProRes 422 MOV. 

I lined it up with some other footage shot as part of the same project. It played flawlessly on the timeline, but when I went to export it, just the clip brought in from the other software had a major audio glitch - the pitch was way up and there was a popping sound throughout the audio portion of that particular clip. 

I was so surprised by this, and tried out different export settings (such as choosing to export MPEG instead of AAC and also changing the Profile, Level, Bitrate, etc) but nothing seemed to work. 

Then on a whim I clicked Send to Media Encoder in Premiere, and not only did the export time increase significantly (from 15 minutes to about ~2 hours for a 9:30-minute 4K sequence), the clip brought in from the other software worked without any glitches.

This has NEVER happened to me before. Any ideas what I might have been doing wrong within Premiere?

I work on a Mac mini 2020 Apple M1 with version 24.6.4 of Premiere Pro.