Control Rig Sphere Trace By Channel Only Using Visibility Channel

I am attempting to use Sphere Trace by Channel in control rig to position feet in contact with the ground.

To keep them from instantly snapping to step on enemy swords and other such things, I thought to create a custom “ground” channel to perform the trace on, instead of the visibility channel. But upon selecting my “ground” channel, the trace seems to still be hitting according to the visibility channel instead.

Here is my trace in control rig using Unreal 5.4.2:

Here is the result of stepping on a cube with the ground channel blocking and visibility ignored:

And here it is again when I turn the ground channel to ignore and the visibility to blocking:

Is this a bug, or am I doing something wrong here? If it is a bug, is there a workaround?