Physics rotation axis lock at runtime

Hey guys. I have a little thing I am fiddling with which lets you lock objects rotation while stacking them on top of one another. In code I do this:

   MainModel->BodyInstance.bLockXRotation = true;
   MainModel->BodyInstance.bLockYRotation = true;

But that doesn’t seem to do it. When I eject and look at the object it has the locked axis checked but behaves as if they are not. If I uncheck and then recheck again while still in PIE mode, it works as expected. Is there something I need to do to apply physics changes in C++ code for it to realize that these have changed or is it a bug?

To clarify, I have a bunchof Blueprints which contain a single StaticMesh each, which has physics turned on. When they are not axis locked they will tumble and roll as intended, and when they are I expect them not to. Setting the locks before entering PIE (using the inspector panel on the right or in the BP editor) works fine. Toggling in C++ does not, even though the boxes get checked. I have to eject from my player pawn, select the object, toggle the checkboxes off and back on again and then repossess my player and it works fine.

Late to the party, but have you eventually solved this issue?