The person answering to several names may belong to several versions of home.

Different names hold different histories. A name for your grandmother, a name for school, a name for the country you moved to or from: each carries its own expectations and its own way of being addressed. Someone answering to all of them is holding more than one belonging at once, which is not confusion but plurality, and it takes work nobody sees. Asking which name to use here is one of the shortest routes to respect.

When you meet someone whose name has variants, ask what they prefer and then use it. If you are the one with several, you are allowed to keep them separate.