Is Ojama king a fusion? If so, did you properly summon it out of your extra deck? In order to summon an extra deck monster out of the graveyard, it must first be fusion summoned
I think it’s just a glitch with the card. This happens with every card you use “cattle call” to summon. It’s not only duel links. This happens on every single automated yugioh game I’ve played. There’s nothing in the rulings that says this should happen.
That's how monsters with Summoning conditions work. Every Ritual, Fusion, Synchro, Xyz and Link monster works the same way as a monster like Harpie Lady Sisters (unless it says otherwise, which generally means it's an even heavier restriction.) They need to be properly Summoned to be Summoned from the GY or banished.
Al, it's part of the basic ruling for monsters special summoned from the extra deck. The card is not the issue, what you need to look up is the special summon rulings, not the card's rulings.