Same happened to me today solo'ing instance. Been killing scarabs for about 1/2hr, gave up, died, respawned to checkpoint hoping it would start fight again at least, but just back in room with endless scarabs. Not wanting to waste another hour on this mission until I find out why.Only reason that may have bugged it was that I stood on vase near window to avoid wall, which did work btw, but even then still had another round of Will of Joko, then Joko, then Will of Joko then the endless scarabs.