Issue with SKMesh Simulating Physics

Hi there. So I was experimenting with the ue4 Mannequin. Under its Physics Asset, I have marked the pelvis as “kinematic”, while all the other bones as “simulated”.
In my test scene, I created a pawn with the following hierarchy, and added two different movement logics to it. one with physics and the other with set world location.

Now some weird things happen. If I move my capsule with “Set physical linear velocity”, the simulated bone will get separated from the pelvis with some sort of “lag”.

However, if “Set world location” is used instead of “physical linear velocity” in the blueprint, the mannequin remains connected while properly simulated.

Please let me know if anyone understands what happen behind the scene here. Also, my goal is to use the physical way (physical velocity, add force, impulse, etc) to drive the mannequin, and have it connected and simulated properly (just like moving with set world location). I have struggled quite a bit, so if anyone knows how to achieve this, very appreciated!