Given how popular they are at the moment I’m surprised this isn’t popping up more often in reports.
If you have a grenade-rifle you are very often (but I don’t think always) unable to use your medpack.
This is especially annoying when you get hit by a large explosion and you jump from one injured trooper to another, none of them able to do anything.
The ‘use medpack’ message still shows on screen but when you hit the button nothing happens.