Drox immune (overhealing?) on phase change bug back again, bug id 1,071,645,203

T16 Cells map with Drox and Maven witnessing. Near-instantly killed the map boss, portal opened to Drox arena. Went in and phased to the shield phase in 1-2 seconds and then Drox stopped taking damage, and began healing to full but I could still see my ailments present on the boss.

Sat there DPSing for about 5-10 minutes with no progress. Left game. Rejoined. Went back to Drox room and killed Drox (who hadn't moved) in about 2 seconds.

I believe this could be an old bug where the Drox phase change causes a race condition where the boss is left in an immune state if you "kill the boss too fast". This is very clearly unexpected and is a bug. Please fix this. Luckily I didn't lose a map or die, but I'm sure other people that experience this are having a way worse experience.

Thanks.