As of 11/25/2020, the Sinbad & Iron Sultan Gauntlet seems to be bugged. After you rendezvous with Sinbad in the Isle of Metallos, Metallos will go through the cutscene like usual but seems to never appear in the actual area. It's just the wizard in a blank duel.
The only way to get out of the duel to my knowledge is to exit the game to title screen and go back in. Multiple player's I've talked to have had the same thing happen, I was unsure if it's an owner-only thing and you must have the owner present for the boss to spawn or if it was just a bug as I did have the same thing happen to me in the Black Palace before you fight the first boss.
I keep having the exact same thing happen to me! I was worried that other people weren't encountering it, but this quells my fears, at least somewhat! I own the gauntlet, and I can confirm that this seems to be happening to every Sinbad gauntlet. I've tried repeatedly, but each and every time I simply have to log out of the blank combat circle. Hopefully this gets noticed and patched, soon!
Same thing as me and my friend wanted to farm since we both had other wizards getting near darkmoor so we wanted the wands but i cant use the gauntlet since the first fight is a blank duel you stuck in till you log out.
James skulldreamer lvl140 james boombringer lvl 93
