Bug: Undoing with the displacement sculpt tool open deselects the face that's being sculpted

[lenship2]

Describe the bug

When using the displacement sculpt tool, pressing ctrl + z will deselect the faces that you're sculpting, while still visually showing the selection grid.

Issue Map

I discovered this issue when messing around with Black Mesa's 4 way blend textures.

To Reproduce

1. Use a 4 way blend texture on a surface and make it a displacement
2. Open the displacement sculpt tool
3. Make some changes, and press ctrl z
4. frustration having to close the sculpt tool and reselect the faces

Operating System

No response