Physics: Lock on axis constraint not working

Hi there,

I have an actor BP which consists of just a Geometry collection, which is a sphere.

I have a few of these placed in the world, and I have an event where I trigger a master field to cause impact to a sphere.

But the master field (and I think also flying-off pieces of the shattered sphere) is also hitting the spheres around it, causing an impulse. This makes sense and it’s fine for me when it comes to X and Y axis, but I need all spheres to stay locked on the Z-axis, because right now they start flying away out of the level.

I saw this “constraint” setting in the physics section, and enabled the constraint to lock them on the Z axis:

But it simply does not work. They still fly away.

I also tried to add a simple “Set actor location” or “Set actor transform” in the “Event tick” node to always keep a certain Z value set, but this also seems to be ignored.

Apparently what I’m trying is not correct, so how else can I make sure the spheres don’t move along the Z-Axis?

Thank you