Bipods won't activate wwhen prone

Bipods won't activate when prone. I tried pressing f to activate, and nothing. This is annoying becasue the attatchment clearly states that you can do it, but cant.

Is the mechanic not designed intuitively and Im just dumb or does it genuinely not work? To me, it seems like its broken. 

It works when mounting on objects. Thats it.

Also, whats the deal with the suppressions mechanic? The visual effects dont exist. This is important when suppressign soemone to know theryr eunder pressure and affected. And 2, its satifiying knowing im doing it as support. That satifaction is gone now.