After Effects project to Media Encoder extremely long render duration

I have exported a 14 second composition to AME and began rendering it in H.264 format at 1080p 50 frames, only to find when I woke up this morning that it has been going for 14 hours and has a remaining time of 129 hours.

I am used to slow rendering but the sequence is nothing extremely difficult. It is a rotoscoped clip with some colour correction and an animated image of clouds behind, along with CC Particle World rainfall over the top. There are no cameras, lights, adjustment layers or anything I'd expect would make it so slow.

This is an issue I've faced over my last few projects, where it has taken around 60 hours to render 18 seconds of footage which, in the end, was corrupted anyway.

It also tends to crash at random points whilst actually editing the videos.

i7-8550U

8GB RAM