"Instance is full" time portal for paladin quest

Quest “Who says you can never go back?”. I accept quest, click the portal. “Transfer aborted: instance is full”.

Me and another pally were running through the quest chain and both entered portal as a party. For a second we were both in the solo instance together as ghouls. Then I got DCed and ported out. Now I can’t get in. He’s still in there.

Rebooting, resetting, dropping and reacquiring quests doesnt work. What a letdown after all that.