Hi, I am losing Altitude in a turn and need advice. RV-8, AF PILOT with ARINC interface on my AFS5400.

All settings for EFIS and AP are as recommended in AFS Manual.

In a Left 90 degree turn I lose 40' then as it levels out it gains 40' then returns to altitude. Bank angle is 31 degrees
In a Right 90 degree turn same thing, but 29 degrees of bank.

ASP - 2.0 , ASI - 0.020 , ASD - 0.20

ROLL - 0.05, LOC - 0.50 , ALT - 5.50 , GS - 3.00 , FD - 1.50

I see the flight director respond quicker then the airplane. It seems the airplane lags a little and then I feel in the seat of my pants the airplane pulling up to get the altitude back, but it seems it needs more "pull" to keep it. Holding the stick I do not feel any slipping of the servo.