NAV-X MXP

First year doing mecanum and at a loss. Thought we would try to overcome drift by utilizing the MXP. Programming in Labview and it seems almost dummy proof, but obviously isn’t since it doesn’t seem to be working correctly. I can see that the MXP is working and providing values, I have values for Yaw, Heading, and Pitch reading to the front panel for testing. I am sending the Yaw directly to the yaw portion of the Cartesian Mecanum.

Does the Yaw only come into play when driving forward? We do go fairly straight forward, but backwards it drifts badly and when strafing it goes diagonally. Any help would be greatly appreciated.

So it appears that the Nav-X is working correctly. Our Mecanum is just not great. I found that the only reliable way to strafe is to do so at full power. Is that correct?