Derelict Mansion Husband Boss bugged

Bug Report ID: #2212080095

I cleared the area and suddenly the boss was not at the courtyard. The wife Avelyne, the Withered Rose was there but Varloch, the Ashen Lord was near the map entrance. See the picture: https://imgur.com/a/vvVuWoG

It took someone else to come to my party, join the map and kill the boss.