Compass issues with Omnibus F4 Pro and HMC5883L

Hello, I have been trying to set up my F450 quad for ArduPilot autopilot. But I am getting a lot of issues with the compass calibration (Gets very very slow at around 35%, and fails after reaching 100%). The “check mag field” warning keeps coming up a lot. In MissionPlanner, the heading slowly decreases.
I have tried moving the compass and GPS module around, but no change. Currently, the GPS module is 20CM away from any other electronics.

Here are the links for the parts: