The software assumes you have the scope sitting at the North Celestial Pole (NCP), that is true north when you start the PMC8. PArk is thus at the NCP.
If you are 15 degrees off, that is a lot of error. If you can see polaris and setup to point to it when in park you should not be that very far away with gotos. The error you have suggests you are not very well polar aligned, you are terribly out of level, or perhaps the wrong mount is selected in Explorestars. If you were running it as a G11, then the motor counts would be wacked by 11%.. this could be about 15 degrees depending upon where you were looking. My explorestars cam by default set as a G11. Maybe yours is too?
Other issues come to mind but given that the mount returns to park those don't stand up to inspection.
Check and make sure your mount type i correct.
Wes, Southport NC
PMC-8, ES ED 127, 10" LX200GPS, Astro-Tech 8" Newt, ETX-90
Polemaster, Orion ST-80 and SAG
Electrical Engineer, Retired