I2c magnetometer not working on Omnibus f4 v6

Sure, for Betaflight. For INAVm I used Fireworks v2 (IMU working at startup). I2C does not seem to have errors when checking status. I disabled uart 3 and attached i2c to to scl/sda (betaflight). Could it be a board problem, or is it something I have completely missed? Have not been able to find a datasheet for this board.