Different results Encoder vs Premiere

Hello,
I've noticed that exports done through Media Encoder has a much worse results, quality wise, than exporting the same thing with the exact same setting directly through Premiere. I started noticing this earlier this year especially looking at texts and still images (like logos) included in the videos. So I opened up a project from last year wich had a perfect image after exporting through Media Encoder and made a new export with the same settings, and the quality dropped. I then made another export of the same project in Premiere directly and the quality jumped back up to the origional standard.

Like I said it is most visable in text and still images so to give you an example I imported a jpg in a 4k timeline and then exported it as a normal 1080p h264 clip, 35mbit/s VBR 2 pass export, once in premiere and once without changing any settings in Media Encoder. Hopefully you can se the difference in the image below: 

The actuall video looks ok on the Media Encoder export but definitely a bit worse than the Premiere export. It's almost like it's been over sharpened.

Anyone know what might be causing this?

Thanks,

Isak