Premiere Pro 22.6.2 Freezes on Mac M1 Max when I Send to Media Encoder

Hi

Whenever I try and send a film that's around 15 mins to Media Encoder I get a spinning beachball that hangs and I have to force quit PP. If I copy the timeline into a new project and timeline, it exports no problem.

I am using PP 22.6.2 on a 64GB M1 Max Mac. This has only started over the last 2 weeks but now seems to be every attempt to send any film I create over 10 minutes long. Shorter films export from the same project. 

I have cleared the cache, have plenty of memory free. I run the media cache from an eternal Sandisk SSD. Files on the internal mac SSD. The films have film convert grading and some text that is pre rendered. Otherwise no other third party plug ins. 

If I export from Premiere Pro rather than send to Media Encoder the file exports no problem. For some reason send to Media Encoder is causing a crash and I don't want to create new projects to workaround this and don't have the time to tie up PP with encoding when that's what Media Encoder does.

Anyone else getting similar issues or anyone know of a solution?

Thanks