For years I've been exporting OMFs from Premiere to hand off to audio mixers without issue, but after the 2019 update I've delivered two projects where in each case the sound mixer told me the OMF was "corrupted" and asked for an AAF instead. They'd have more success with the AAF but there would be tracks completely out of sync and no metadata or labeling that follows.
In each case there are no merged or nested tracks in the timeline.
For OMF, I'm exporting with media enclosed in a single file, trimming audio to 60 frames.
Looking around there seems to be a lot of issues trying to get audio from Premiere to ProTools, but no solutions or workflows offered. Audio mixers aren't going to move off ProTools anytime soon and I shouldn't have to move to Avid just to accommodate the audio mixer. Past this, the only thing I can think of is to export each audio track as a separate WAV and tell the audio mixer it is what it is, but I don't find that to be a solution.
What is an actual working solution to to get my audio timeline out of Premiere and into ProTools so audio mixers can start working?
Some users have reported having better luck when exporting the OMF and AAF files from Audition. So send the sequence from Premiere Pro to Audition, and export from there. Worth a try.