[STPG Press]

Today I tried again. Did 180 degrees for 180 seconds and it printed th the edge fine, but you can see where the black goes brown in the middle of the mug.

Where are you located? Is there a heat press supplier or even another business that does dye sub on mugs near you? Maybe a little business to business consideration to let you test your mugs in their press.

I don't know anything about who you bought your mug press from. Maybe it is bad. When I got my standard 12x15 heat press last year, I had to replace my platen after the 3rd time I powered it on. Been great ever since, but problems can occur with new equipment.

Good luck.