Exporting Glitch

Glitch

Screen Shot 2022-01-26 at 16.09.55.png (599.47 KiB) Viewed 204 times

I'm working on finishing a short film that was shot with a Canon 6D, not a log file, but I'm working on the clean-cut of the film edit in Final cut pro and 1920x1080 apple proress file.
I did the color correction on my Mac mini 2.5GHz Intel Core i5 -16 -1600 mhzddr3 - AMD Radeon HD 6630M 256 MB, not a very fast one but did the work fine with a little bit of patience, but the problem is when I export, every time I export as QuickTime, H.264 or ProRes files a glitch appears in the final file that doesn't appear in the timeline... this is an example.

this glitch looks like a color clipping and is about one frame or 2 frames
I honestly don't know why this happens, even using the pre-sets to export this happens. I didn't find information about this. What happens and what am I doing wrong? Can someone help me

Thank you.

You need a stronger machine, your GPU is far below spec.