I have a 64" Edge (a no name arf kit I got on RCU a year + ago). It has an unusual knife edge behavior. I roll it onto knife edge, give it some rudder to keep it flying and the rudder input rolls the plane back to level. I can compensate by giving aileron but what the?

I checked the angle of incidence - wing to horizontal stab and they are dead parallel - angle is 0. The wing alignment pins are adjustable if need be so the angle of incidence is adjustable.

Wing is fully symmetric, tail surfaces are flat - no airfoil.

I no very little about aerodynamics, could someone tell me what I can do to eliminate the adverse roll coupling - I don't want to do channel mixing.

I notice that the rudder planform is not all that scale - more tall/narrow than others I have seen - could that be causing it where there is more surface area above the thrust line than below it?

Thanks in advance.