Captain Haunt not working properly

on round two of fighting Captain Haunt , I killed off two of his shield generators, and then he runs around with his shield up, and there is no third shield generator to destroy. Has happened twice now. Makes this event unplayable, since I cannot break his shield.

It’s a glitch that happens when you start taking out the generators before they all spawn in. Just wait a second or so before you start shooting them.