I've never heard of them or tried them, but based on their folded shape, they look more like some kind of dumpling to me, than a ball.
Balls are servings of the food rolled into a round shape, such as meatballs. Dumplings tend to have a filling inside some kind of dough that's been folded over and pinched shut.
They look like some kind of pierogies in sauce, to me.
However, if I was familiar with them, I'd just call them by one of the names you list. I think we've mentioned before that when discussing foreign foods, English just tends to borrow the name from the original language.
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