Help diagnosing odd Naza control response (especially in Manual mode)

[HerkyBird]

I'm starting to try and get to grips with the Naza on my 350 size symmetrical quad in manual mode and it's not behaving as I believe it should. It's kitted out with standard DJI motors, Esc's and 8" props so it's effectively a F330.

No matter what my gains, the quad feels unstable in the pitch attitude in particular in that if I dip the nose and let go of the sticks, rather than locking in place it tends to continue to increase it's pitching forward, the reverse happens if I pitch up. I'm not sure if the same is happening in roll as you tend to 'fly' that axis more but it certainly doesn't feel at all 'locked in' like my old KK2.0 did. The balance is spot on so it's not that. My Gains are currently as below although I have had to drop the basic gains down even further as if I open the throttle up too quickly or too high I get a very high frequency left/right oscillation. Atti/GPS modes seem to behave better although even then, I still seem to get more wallowing or wavering than I seem to see in other peoples videos.

Does anyone have any ideas please?