Ancient Gear Castle on the field, then I play Tribute Burial to summon Ancient Gear Golem but I can't use Tribute Burial effect, game only appear option to use Ancient Gear Castle effect. Is this a bug?
Yes, condition is fulfilled. If I set Ancient Gear Golem, Tribute Burial effect will popup. Just can't normal summon with Tribute Burial effect.
Did you and your opponent have at least 1 monster in the graveyard? Else you can't use Tribute Burial's effect?