Not sure if trackers are still supposed to lock on to homing missiles, they don't for 1.12.2

When tracking a player on 1.12.2 (I believe the tracker is supposed to point in the direction of the player when you track them) That doesn't work also

Trackers and homing missiles were removed because they didnt work properly / were too op. Not sure if we will add them back in a future version, but for now they are gone, sorry!
(They might still be in the latest Release version, but they are definitely gone in the 4.x.x alpha)