Zarokh insta killing on hourglass phase

Was fighting Zarokh today, in a party of 2. We got him down to about 30% hp pretty quick ( so "skipped" ) the first hourglass phase. We did one round, colelcted all 6, went fine. Then about 6 seconds later he popper up another hourglass phase, but even before we could start moving, he did the instakill, not even giving us the opportunity to try and collect the hourglasses.

Bug Report ID: #999645873
Video : https://youtu.be/MasdGSMnaVs