Fun fact: ẞ, ẞ’s lowercase, ẞ’s lowercase’s uppercase, and ẞ’s lowercase’s uppercase’s lowercase are four separate strings.
Yep, because ẞ is only a relatively new thing, and still not really standardized in most places.
ẞ lowercase is ß (which is correct, as in Gießen - GIEẞEN)
ß uppercase is SS (which is correct, as in gießen - GIESSEN)
SS lowercase is ss (which is correct, as in Hessen - HESSEN)