Tried exporting a 1 hour HD pro res QT file to HD mp4. Media Encoder slow as hell. Estimate job time reads at 1 hour and 20 minutes and it crawls through and eventually hangs about 20% of the way though. Tried updating 2019 and also tried using 2018 Media Encoder.
I eventually resorted to opening my old Media encoder 5.5 which is speeding through the encode in 40 minutes. Perhaps Adobe know something about this glitch.