Issues with BSP Brushes

I have been having a confusing issue with BSP brushes just shortly. I’ve started a new project and used a map with nothing in it, one of the options when creating a new map. However, my BSP brushes are wonking out on me and doing something that is very confusing. Here is a screenshot.

I have no idea what is causing this issue. Thank you all in advance for your help.

Is that the only brush you have? it looks like an oldskool bsp error.

I’ve got a few more in the map, but they all do things like this. I’m at a loss as to what’s going on.