Honestly this was never even confirmed a bug the community just called it a bug because it's annoying and with how much it's talked about bungie would've replied to someone at this point but nope. Bungie likely are afraid of Mantle being too strong and this is their way to try and balance it don't forget they made it give massive penalties and when they buffed it by letting you cancel it and removed the cooldown penalty is when it started happening and it only happens in pvp modes.