Please remove the 20 character length restriction on passwords. When using a password manager it is trivial to generate a secure password much, much longer, and limiting the length to 20 characters serves absolutely no purpose. The back-end system should in any case /ONLY/ be storing the salted hash, which does not care about the length of the original password. If this (salted hash) is not the case, then I must beg of you to correct this as a matter of extreme urgency.