Cannot share FCPX project without randomly pixelated and overlapping/ late frames, please help!

Hi all,

I’ve created similar projects on iMovie for years and never had any issues - this is my first attempt using FCPX and I’m not impressed so far...

Every time I render my project, a random assortment of the shots will be pixelated and glitchy, often with some frames of those shots flashing up later in the film.

I’ve tried using different codecs and different resolutions. I’ve tried using compressor. I’ve tried rendering through FCPX and then using compressor. I’ve tried deleting all render files/ background data etc. I’m utterly perplexed!

I’ve had no performance issues with my MBP, and I’m running the latest version of FCPX. The film renders perfectly fine within FCPX, it’s just on the final share that the error is occurring.

https://youtu.be/Bbvr2J1AJ2Q

You can see examples of the error at:

1:51, 1:58, 2:19, 2:23, 2:25, 2:29, 2:32, 2:37, 2:39, 3:16...

All of the clips used were shot on iPhone so they should all be the same format if I’m not mistaken? One shot was a slo-mo that has been sped up (not sure if that would create a frame rate mismatch issue or not), but that shot has never had an aberration/ glitchy patch. Some levels/ exposures/ saturations have been tweaked, but that’s video editing bread and butter, surely that can’t be the issue?

Any help or advice would be appreciated.