Interesting. It really shouldn't work like that. Acute, grave and tilde (~) are included in all western kb-layouts, even they are rarely used or needed. I can imagine an American might go through his whole life without needing them, although some words of Spanish origin with tilde are quite widely used in modern American English: jalapeño, piña colada, piñata, El Niño etc.
I'm only using one of them (acute) when corresponding with a friend of mine, Renée from Utrecht Holland.
I'm sorry I can not help you, I really don't understand why your keyboard is not working as it should.