Or, perhaps you are, if you go by the question's previous incorrect definition

I'm not sure why I knew that one but when I saw that option something just clicked and I knew I'd seen it before somewhere. I think it must have been from my years of reading Wilbur Smith books growing up haha

It does, because ß isn't actually part of the alphabet. It's a ligature, not a letter, meaning that it was actually formed from and represents the combination of two other letters (in this case, "ss" or "sz".) It's similar to how you sometimes see "æ" in English representing "ae," or how the Latin word "et," meaning "and," turned into the symbol "&," but "æ" and "&" aren't considered part of the English alphabet. (Though, to be fair, there was a period in the 1800s when "&" was taught as the 27th letter of the alphabet.)