Audio sync issues on project

Hi Everyone,

I had a young editor do some work in Premiere, although he was not as versed in Premiere as another editing format. Imported into Premiere were 2 files of filmed footage from 2 different iPhones. (I'll call them "Part A" and "Part B".) Task was to edit both parts and then put them together (linearly, one after the other). So far so good.

Upon outputting the finished file, audio sync went haywire on the second part, Part B. Whether making an mp4 or a m4v, sync is messed up.

Any ideas why this might happen...?

IF the frame rates are different with these two parts, would that cause one of them to go out of sync when outputting? EVEN when it's totally in sync working & viewing in Premiere?

Maybe these are dumb questions... but I'm not an editor. (But looks like I'm going to need to hire someone to fix this, though.)

Thank you.

I'm not sure why it's happening, but what format did you cut in? Perhaps try exporting the timeline as it is natively, then making this file into a MP4 in AME or by bringing it back into Premiere.