C4 not working at all

Twice I had three c4 planted on a tank, push the button and absolutely nothing happened. Why is that a thing? Even if the tank had anti explosive on, which it didn't cause it didn't see a green light, the c4 still should have gone off and killed people and equipment around the tank, but nope. It's like I planted duds. Nothing happened at all. Used to be that c4 was the answer to tanks camping at the back of the map with a crew keeping them repaired. But you can't even do that anymore. Excellent balance 👌. Great job rewarding campers not playing objectives