They are not quite the same, Sweeties is just a word that is different in different dialects of English. The course writers do the best they can to accept all the options, given the time it takes (which they give for free) and their limited knowledge of the range of English dialects.
But haggis, neeps and tatties is different. This is not just about how to translate three food items that you might have on your shopping list. Whatever you call them when you buy them (potatoes, spuds, tatties - neeps, turnips, swedes, rutabaga), you then take them home and prepare a traditional Scottish dish which is unambiguously called haggis, neeps and tatties. Thus the correct translation of taigeis, snèap agus buntàta depends on whether it is meant as a list of three items on you shopping list, or a prepared dish.
Since it is the English word sweeties in origin, it may well have a pronunciation that does not match the Gaelic spelling. This is quite common in borrowed words in Gaelic. In this case there may well be a w in it. Now many languages, including Gaelic, and with the notable exception of English and Welsh, regard /w/ and /v/ as interchangeable. So /sv/ would be plausible, except that it is almost imposible to say - it would be likely to become /zv/ or /sf/. Since there is no /z/ in Gaelic, you are left with /sf/. Make sense?
As a general rule, you should ignore the Gaelic spelling if the word is borrowed from English.
You should not call anyone daft just because they do not understand something you understand. In this particular case it is not obvious how an American would understand suiteas if the only translation given is sweets or sweeties and they do not have these words in their vocabulary in the sense of 'candy'.
Community Guidlines (extract)
Always be Respectful
We come together from across the world at varying language levels with the same goal in mind - to learn. Curiosity, questioning, and cultural understanding are something we celebrate. Be respectful of others and where they’re coming from.
Embrace and share regional language differences
A language can have many words, accents and ways to say the same thing. We think that’s one of the wonders of languages. Approach these conversations with an open mind and attitude.
Thank you for backing me up. It is worth pointing out that whilst Duolingo has a policy of non-discrimination they also have another, totally contradictory policy of writing all courses in American English. This results in them not having any guidelines or software for dealing with the problem we have here. There is a specific problem on courses like this that are written by people unfamiliar with American English.