Czyja rodzina je obiad/kolację?

Both sentences feel unnatural to me.

That's definitely wrong, that would mean "Whom parents eating dinner"

It should be. "Whose parents eat dinner?" is a very unnatural sentence of English. "Whose parents are eating dinner?" would be much better. Unless it is actually meant to imply habituality, as in, do they ever eat dinner, but I'm pretty sure it's not, as I don't think we've learned that yet.

Yeah, "are eating" makes a lot more sense, it will be the default now.

We don't have the power over what typos get accepted and what typos get rejected.

'dining', with one n. OK, added.