Good morning,
I ran a few more tests over the weekend. The looping waveform happened no matter how long the zoom prefs were set. No difference between 512 and 1024 samples in PT HWB settings. I was tracking a 32 channel session.
Here's a link to a better image of the looping wave form.
https://www.dropbox.com/sh/kn8xehz97...kVpDgB0da?dl=0
I'll upgrade to 20.1.0 this week. Thank you!