Alert carry, more commonly known as simply lowering your weapon, doesn’t work.
When you lower your weapon using the button combo, it disappears from your screen as if you successfully lowered it. However, if viewed from third person (theater or another player) then your weapon is still raised, even if standing completely still.
It was like this in the beta, thought it was just an early build issue. This has to get fixed. Thankfully, though, this is the only issue I have found with this game.