I have worked through a TON of troubleshooting on my previous PLA printer(Voxelab Aquilla). The toaster torture test is a beast of print, and it is meant to fail and find the limits of your printer. I would start with much simpler tests. Have you done any simpler temp tower or chep cubes? Or any of the bed level prints? Share photos of some other prints so we can get a better idea of what all is going on.

I am not familiar with how monoprice printers work - but what slicers(s) have you tried/used? Are you leaving default speeds/temps? Is it always the same filament?