Same problem here... still 2024
Work around: We killed the person who was not present in our coop. Then asked Withers to look after him. Though he did not disappear from our group right away, we quit game and logged back in and finally talked to Withers again and he was gone from group and we finally had space for Shadowheart so she could talk to Ailyn so we could continue our adventure. Honor mode saved at least for a moment
