P4 seems to sit a bit bent tried resetting the imu and compass with same results, below pic is with it hovering in place very little wind it doesnt drift much but just doesnt look straight.
Have been told it's a upgrade module think it's about £80.
https://www.modelsport.co.uk/dji-hdmi-output-module-phantom-3-pro-adv-and-phantom-4-/rc-car-products/403180
Had a look on the Web and it looks to be £30 new and even if I do say £15 plus delivery and fees that's gonna be around £20 mate can put up some pics if you like?
And I just sold my mfu