Man Lock on/off coverage

Could someone help me understand what I'm doing wrong when I press coverage audible I thought it was suppose to help defenders cover there man better,but seems like when I do it my men switch positions move all over the place especially my linebackers,so say for instance I press man lock on first and then call a 4-3 under cover 3 zone and press coverage audible what suppose to happen or what if I press man lock off and press cover audible what suppose to happen.It confuses me on when I suppose to use coverage audible and when not too.Should I do it with zone or do it with man coverage and most of the time when I do do it my men be all out of position.What am I doing wrong?Please guys someone help me understand.I'm just trying to make my opponet think I'm in a man when I'm really in a zone.

I believe it just lines up your defender with a man, so that it looks like you are in man coverage even though you are in zone. If you zoom out before you hike the ball you can usually tell if the defense is in a man or zone, so from my understanding it really doesn't help that much. It may help a bit if they have an overload to one side perhaps, but overall it just lines up your defender to look like man coverage

Man lock means that you corner, safety, of linebacker is going to follow their certain assignment if they are put in motion. You could be in zone, but it makes it look like you are playing man.