Encoder getting slower and slower

I have to export a bunch a short videos for Social Media. 
they are round about 50 videos. 
After the first ~30 getting very fast (2-3 Minutes each. 
than its slowly getting slow. now i have round aboud 20 to go and Encoder is "reading the xmp" for like 30 Minutes on each. 
i have tried to reinstall encoder and after effects. First Vid after go well, then this error hitting the same as before. 

please help! 

i have 
i7 -10700
32gb ram