Laggy Yaw Behaviour with F450 Frame and Arducopter 4.0.2

I’ve been flight testing a new F450 quadcopter build. I fly it up to about 20m and do a 360 degree yaw. I release the yaw control of my transmitter when it reaches a full turn, however the drone keeps on turning for another half a second (about).

What could be causing this problem? Do I need to do an autotune? I did notice that the GPS/compass mount was “wobbly” which I’ve fixed but been unable to test due to the lockdown.

I’d appreciate any feedback you have. Thanks.