File suddenly exporting much bigger

Hi everyone,

I'm having a weird problem when exporting my Premiere project.

My projects consists of AE compositions directly imported into Premiere. Its a 6 mins simple explainer video with very clear cut graphics a little music and a voiceover, so nothing fancy. I have exported this video twice already, both time with the H.264 codec and the Youtube 720p HD preset. Both times the rendered videofile had a size of roughly 76MB with a bitrate of ~1200 Bit/s.

This morning I wanted to export it again with the same settings after optimizing a couple of timings in After Effects and now it suddenly exports as a ~770 MB file with 12000k Bit/s and I cannot see any reason why.

The changes I made in AE were just moving some keyframes a little left or right, thats all.

I tried resetting Premiere by holding alt during startup, I even redid the whole project, but to no effect. It still goes for that large filesize.

I'm going crazy here - any idea, experience or advice is highly appreciated.

Thank you all

Claudia