The German language has both a a formal (Sie in both singular and plural) and an informal (Du/Ihr) address. Currently the German translation of Jellyfin seems to be an inconsistent mix of both which really isn’t ideal and should be made consistent to one form.
In the context of software that is professionally used the formal address is nearly always used. Other kinds of software like FOSS projects may use one or the other whereas projects styling themselves as “lifestyle products” tend to use the informal one.
Projects like Nextcloud have solved this problem by offering both versions but in the case of Jellyfin I really believe we should just stick with the informal variant. Using the formal one just makes a lot of sentences feel overly stilted and complex (the complexity is due to the formal variant always requiring a pronoun whereas the informal one doesn’t, i.e. “Legen Sie ein Profilbild und Passwort fest.” vs. “Lege ein Profilbild und Passwort fest.”).
I’m interested in what others, especially speakers of German and other languages with a similar problem, think about this.