I’ve ran into this same issue numerous times on different platforms. They silently enforce a max length, unannounced to you, then you can’t log in later until you figure out the correct length.

I guess I don’t really understand the reasons any engineering team would limit password length, but at least implement in a way that is apparent to the user. Successfully saving a password that is different than the user expects is wild.

Moreover, in the case of a financial institution like Vanguard, limiting password length feels particularly offensive.