Rust Experimental - Can't Build !

Ik people think building is straight forward in experimental, and it is. I’ve been told by everyone to right click w/ the foundation for a menu to pop up so you can choose which structure you want to place.
But this doesn’t seem to work at all for me. My mouse it defiantly NOT borken, and using other items in the experimental (like scopes for weapons) works 100% fine. I have tried changing the controls from
the start up menu and still it doesn’t work. Any suggestions?

You need to have a building part in your hotbar, choose it, then you can access the rightclick menu.