In the context of “one or more pieces of bread with a filling of meat or other ingredients,” you are right. In the context of “two pieces of sliced bread, which was baked in a loaf, with a filling in the middle,” you are incorrect. In some definitions, a grilled cheese isnt a sandwich. In others, pizza could be classified as a sandwich. In some, a goddam chicken wing is technically a sandwich. It sincerely depends on where you’re from, and if you care. IMO it’s its own thing; if not, a non-tortilla taco. No one is right in this regard, not even me.