This is probably the exact same bug as https://answers.ea.com/t5/Bug-Reports/HvV-can-t-use-abilities-after-stun/m-p/6470892#M1710
Please report this bug as well over there.
If you get stunned (works in different ways) you have a chance that your abilities will go into locked mode (they turn grey) and you cannot use them (or even jump). The only way to activate them again is by (respawning or) getting stunned again by the opponents team.
This also isn't specifically about the Choke, it happens with most of the stuns. The bug is in the game from launch.
