Don’t think this has been reported yet.
Steps to reproduce:
Create brush, rotate any angle then click align brush vertices,
Does nothing as of 4.7P and was working fine until 4.6.X
Thanks.
Hi ,
This seems to be working as intended from what I can see. When I hit “align brush vertices” the vertexes all snap to the nearest grid point they can while maintaining shape. What preview are you currently using?
I’m currently using preview 3.
I have tested this a couple of times (including about 5min ago ^_^) and also have asked someone else to confirm that they are getting this behavior. 
edit: Dunno if it’s relevant, but I’m using the launcher version of the editor.
Also made a video [seen here][1]
[1]:
In the bsp brush, try right clicking each vertex to align it to the nearest grid snap point. Then press the align brush. Does this revert the brush back to its original position for you?
Hi ,
Yes, it does. Right clicking each vertex in the normal mode just snaps that vertex to the grid and then the others are off. In geometry editing mode, the vertex does not move.
In either case, hitting align brush vertices returns the entire brush to the original position.
Hi ,
I was able to reproduce this and have entered a bug report, UE-8113 to be assessed by the development staff.
Thanks .