My god Pro Subharmonic 2018.1 is a mess. Each time I press play I can get a different output. (Protools Ultimate 2018.7). Nobody at Avid is beta testing? I've found this after 20 seconds...
/edit
Same thing happening with 12.7. Could be a PT 2018.7 issue.
So far, when set to DSP it seems to work fine. When set to native (same as offline bounce i guess) the output may vary each time I press play. This is most notable at the Resonant 1 drive setting (full wet mix). Using a 100Hz sine.