Bug Probuilder connect vertecies rarely seems to work and gives no feedback.

Lets say I'm doing this very basic case of trying to make a hole in a mesh.

I'll start with making a big wall with probuilder.
I'll use "Insert edge loop" tool on each of the 4 edges to then make a square in the middle



Next I'll use "Delete Face on both sides of the wall.



So at this point I'd like to fill in the 4 empty sides of the "hole"

I could try to select 2 vertices and connect them for each corner like so:



Pressing "Connect Vertices" just deselects the two verts without any error or message. And sadly these two vertices refuse to be joined

Now if I use "Bridge edges" on the edges it will fill in the walls, but this does not explain why I can't connect the two vertices.


More importantly, why does this, and most other probuilder commands just silently fail without giving any feedback about what is actually happening?

https://docs.unity3d.com/Packages/c...tices tool creates,to keep the geometry valid.

The example in the documentation shows them connecting on an existing face, and if I try that out myself, sure enough it does connect when the vertices are already on the same face.
But I do not see any mention of the conditions that would make it work, seemingly implying that my example case should work.

I am using Unity 2021.1.10f and probuilder 5.0.4