This points to an issue of what “character” means to your password process. When people say “8 character passwords are perilously close to no password at all”, I read that as “8 character ASCII passwords are perilously close to no password at all”. If your password includes non-ASCII, your encoding comes into play. In UTF-8, every single non-ASCII character will be two or more octets. That effectively doubles the length of the UTF-8 characters.
(I purposely avoid all non-ASCII password characters myself, because I have a pessimistic view that all interfaces will encode the same way. ISO-8859-1 or worse, Windows codepoints, may lurk somewhere; and a string of *********** gives me no way to check encoding.)