High compass offests

I have a Redcat Gen7 Pro That I have installed a Pixracer flight controller and a GPS/compass on.
I have calibrated the compass several times outside away from any metal and I get offsets in the 400-500 range.I also fly quadcopters and never have offsets near that high. I’m wondering if the type of esc on the Redcat might be causing the high offsets, the compass is almost 5" away from the esc so I don’t think that could be the problem but I could be wrong.