I have a Matek M8Q-5883 GPS w/compass and a Matek F405-WSE
And put it in a Sonic AR-900mm Wing
And now I having problems I never had before and the FC has a large piece of foam between my flight controller and the mounting base it came that way should I take the foam off it does cover the barometer?

1. my altitude in my googles disappears after around 300ft then later comes back. And it isn’t close to being correct.
2. My Home direction is way off.
3. Someone told me that having a compass in a Wing can really give you problems and said I should turn the compass off.

A barometer depends on atmospheric pressure to estimate altitude. Foam should not be creating a constant pressure chamber (there has to be some air leakage) and thus should not affect it much. Further more the altitude you see on the OSD is a combination of GPS altitude and Barometer altitude (this is ow it works in Betaflight by default, I am assuming iNav should be similar).

Your home direction is way off? Do you get a GPS lock before you take off? What is the minimum number of satellites you have set for a GPS lock? To calculate the direction to home the flight controller needs a relatively accurate home position prior to take off and a relatively accurate GPS location of the model during flight.

Compass inside a wing maybe? But on a wing, why? As long as you keep it away from any electrical interference it should be fine. Perhaps you should mount the compass away from the main fuselage like perhaps on a wing and definitely away from the ESC and motors or any electrical wires.

i get 14 and sometimes more Sats and I do get a gps fix.
I might have to change the location I had it on the wing before but 2 friends hove same model and put there compass in rear to the side outside where the ESC and motor is located but they have no problem with theres but I have different compass I have a smaller but better compass. See pictures:

my friends location:


My location:

Maybe your ESC/Motor is creating more electrical noise compared to theirs.

Try moving your position on the plane if the GPS unit works perfect on the bench.

I will try it, my lost wing had it on the wing out about 4 inches away from any electronics.