Animation Offset Preview is Jittery

I’m working on setting up an amination offset. I got the poses from the Lyra project and want to use them with the Quinn character in 5.6. I’m experiencing jitteriness when setting up the Additive Settings in the poses. From my understanding, the Additive Anim Type should be set to Mesh Space. The Base Pose Type should be set to Selected Animation Scaled and Base Pose Animation should be set to the Idle animation (not the AO pose). But when I set the Base Pose Type to Selected Animation Frame, all is well. All of the animations and AO poses have been retargeted to Quinn (not Quinn Simple) and the skeleton for the Aim Offset and animations are set to SK_Mannequin. Are my setting wrong?