I have to calibrate my P4Pv2 every time I drive out to an new location. Is this normal? I just replaced my GPS, could this be the issue?

Hello there. Good day and thank you for these information you have given. DJI recommends to calibrate the compass of your DJI Phantom 4 Pro V2.0 in the following situations:
1. Flying at a location further than 31 miles ( 50 km ) away from the location the aircraft was last flown.
2. The aircraft has not been flown for more than 30 days.
3. A compass interference warning appears in DJI Go 4 and/or the aircraft status indicator blinks red and yellow alternately.
In addition, if the issue will still persist and as posted above you have replaced the GPS of the said DJI drone. I would recommend for you to contact our DJI Support Team at https://www.dji.com/support?site=brandsite&from=nav for further assistance. We will do there best to help you and give out the best resolution for the said issue. Again, I am sorry for the trouble and thank you.

You've been given some copied and pasted misinformation in post #2.
There is no physical reason that you would need to recalibrate the compass in cases #1 and #2.
Neither is indicated in the manual, and if they did, they would be wrong.

And in case #3, the correct action would be to power off teh drone and move away from the source of the magnetic field interference and start again.

In your situation the first thing to check would be what the sensors section in the app settings tells you about your compasses.
Are both connected?