Physics Constraint - Lock Rotation is World Relative

When setting the ‘Lock Rotation’ physics constraint on a component that is simulating physics, the X,Y,Z are world relative, and not BP relative, and there doesn’t appear to be a way to change that.

For example if I had a pendulum or bell BP where the object can only swing a certain way relative to the BP it would not swing if that BP was placed in the map at a 90 degree angle to the locked rotation.

I’ve included an asset. Add two copies of the asset to a map, one rotated 90 degrees on the Z axis, and simulate. One should begin to rotate correctly, the other will stay stationary.

You could change the Physics Constraint mode to Custom Plane, but that doesn’t sound flexible enough for your use case. Instead, check out the Physics Constraint Component, which should have a lot more options and flexibility for what you need.