I have 2 cubes in my level. One has a socket in the middle of one of its faces called “SnapPoint”, the other has nothing added.
When I right click the normal cube, and select “Attach To” and choose the socketed cube followed by the “SnapPoint” socket nothing happens and the chosen cube does not snap to the socketed cube like it does in 4.18.3. The normal cube does become a child of the socketed cube, but that’s it.
Clearly this was broken in the new version - or - there’s some added step or switch/option I’m not aware of that needs toggling.