Encoding Problems in 2019 Premiere, AfterEffects and Media Encoder
I have had lots of weirdness with Dynamic Link recently with the latest versions of creative cloud 2019. 
Sometimes it goes really slowly when you have projects that include linked AE comps in Premiere. 
I would try exporting any comps from AE as proRes files, into premiere. Then exporting your videos directly in Premiere without using Media Encoder, and see if that makes it any quicker.