"Hello, we've found a quirk with ABP's pose watch and compatible skeletons. Same setup as above. We have skeleton A as the base and skeleton B as a compatible skeleton. They both share similar hierarchy (although not identical) The ABP has skeleton A by default but will use skeleton B at runtime. Pose watches look correct at preview time. During runtime the pose watches look incorrect. However, setting the PreviewMesh at runtime to skeletonB fixes the problem. I couldn't find a relevant bug in the system but I wasn't sure if it was the intended behavior."
The pose watch in PIE and in the persona viewport match and appear correctly
The pose watches do not match.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-161450 in the post.