Supress enemies with LMGs still bugged or doesn't work. Any fix yet?

In case you aren't aware, you can only suppress someone who is injured, because all it does is reset the timer to when they can auto-heal.
So you have to shoot them, not kill them, then shoot around until you see the "Suppress" - all before they kill you. 
If you sit back and hope allies can hit but not kill them, that's easier...but not easy. 

It's a stupidly weak mechanic, and is very counter-productive as a challenge.