Visual physics difference between Client and Server


When running this character floating in Studio, it all works fine.

When actually playing it, the client sees the character ‘falling’.

If I put the BodyPosition’s D,P and MaxForce all to nothing, the character obviously doesn’t float, but it actually keeps the propeller (welded to the hand using a WeldConstraint) above itself.
When increasing the P value it floats up and falls into this wrong state…

When the WeldConstraint between the object and hand is disabled, it all shows correctly - even on the client.
Also when killed and a copied model has been :MakeJoints()'ed, it does work fine on the client as well

Anyone knows what’s causing this strange visual behaviour?