India Government's official Website for managing public retirement fund, NPS, eNPS does this. Password need to be changed every 90 days, of max 14 characters length, but no where documented. On password change page, it will silently accept your any 14+ length password & will truncate it to 14. Then you try to login with your actual password, it gives error, Wrong Password.
In the U. S., Washington state's initial rollout of their ACA site did that. Gave it a big, long >20 char password, it created the account, go to log in and...
How did I figure out what was going on? They would happily email your password in plain text. </facepalm>
Personaly I like mobile Id which makes logging into PostFinance or swisscom easy but not all phone providers are able to offer it.
Sucks that for post and sbb I need yet another system, Swiss id....