[Solved] Sound wrong/out of sync when exported

Whenever I am in my project (Premiere Pro v 14.0.3) the audio is in sync as it should be, but when I export it (both through Premiere or Media Encoder) parts of the video's audio is completely out of sync. It seems that the sound is taken fromt the same project, but a different part of it.

This only happens to certain files, as other parts of the video is completely fine. I've tried to delete all cache files, but nothing changed. I've tried to export as H.264 and Quicktime, without any difference. I tried "replace footage" on the troublesome files with the same footage, but no difference.

How to solve: Right click on your material in your project and select "Properties". If it says "variable framerate detected", download and use Handbrake to convert to Constant Framerate. Video below tells you how it works.