Glitching

I have used the Adobe stock footage for a project and the in-program Overlays, titles etc. It was very glitchy at around the 18 second mark every time. nowhere else in the 2minute video is it doing this. I have spent a total of 3 and half hours with various Adobe techs and all their suggestions and stuff havent worked. No matter what elements I add or take out of the project, no matter what settings I change, or what stock footage I use (even the ones that I run through the Handbrake software to make the FPS the same) it always glitches at the same point. Any suggestions before I delete 3 months of work and start again?