I think you make cheese. Yogurt cheese in my experience is just strained yogurt, it comes out sort of like cream cheese. What you describe sounds sort of like paneer, which is made by adding and acid to hot milk to form curds. I think if you were to continue to cook paneer, you would end up with something that resembled fondue, which is what it sounds like you have. The lack of acidic taste to me says that it didn't make yogurt. Could it be that the milk was too hot and you killed the starter, but the acid in the starter made cheese?
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