i dont know what causes it, but while doing the Altars of Summoning i encountered a bug where vexcalibur suppresses anything it touches. I put up the shield and it gives me a void supp. debuff that switches between 1-5 seconds on the timer until i release the shield. It was also suppressing enemies that i shoot and teammates that i shield. i was on a void warlock with melee/grenade fragments and karnstein armlets, it might have stopped when i took off Echo of Persistence (the buff duration extender)