Audio quality is different on timeline and after export (worse)

Hi,

Could someone please help me figure this out? I am trying to work on a video (16:9) format. My audio is from Artlist.io and originally great quality. On the timeline in Premiere Pro it sounds great and clean sound. After I export it, the sound is horrible, not clean at all, is muffled and bad quality. Do you have any idea why? I didn't do any adjustments to video files or audio file except to cut/trim video files and put them together. Attached I am sending the picture of my export settings. Also, I have new macbook, and the newest version of Premiere Pro, updated, installed everything.

Thanks for any ideas or support. Anja