Random black frames in export

I am having such a frustrating time exporting videos.

I work for a local lifestyle social media platform that makes daily vertical videos about the community.

I dont exactly know when it started, been half a year i'd say, but on 80% of my exports, ive been getting 1 or 2 black frames in the final product. HOWEVER, on the export, only the VIDEO has the black frames, and not the captions. So for that frame, the captions are still visible. And on each export the black frames may appear in completely different spots.

• My temporary solution is having a co-worker export projects for me, thinking that it is something with my machine. BUT, recently they were let go, and i had to shift to his station. To my surprise, my exports STILL have the black frames.
• Then i thought maybe i adjusted my export settings differently from my co-workers, but it turns out they are EXACTLY the same settings. I've still been exporting on ANOTHER co-workers machine under their account, and it turns out fine.
• Thinking this is an Adobe issue, we reinstalled it on the machine, still black frames.
• Thinking it had something to do with my account, i signed in through someone elses account on my computer, still black frames.
• I reset the cache, render the video before export, export using Media Encoder, lowerd the outout quality, and a multitide of other random tricks i have found on this forum and Reddit, and still nothing.
• I also get random dips of black whenever i use a standard transition like a cross dissolve.

It seems the only universal factor is ME, and i'm starting to lose my mind a bit.

I wouldnt be here unless i was desperate. Please help.