In password security, the longer the better. With a password manager, using more than 24 characters is simple. Unless, of course, the secure password is not accepted due to its length. (In this case, through STOVE.)
Possibly indicating cleartext storage of a limited field (which is an absolute no-go), or suboptimal or lacking security practices.
At least they tell you. I signed up with websites that just cut the password after the 12th character. No way of signing in with the password again (not without trying a couple of times, at least)