Are you using a straight ssh connection with username and password, or are you using a public/private key pair with a passphrase?
I wonder if, rather than Ansible asking for your password, the underlying ssh connection credentials were cached, expired, and needed to be refreshed?
For example, I use a smart card and PIN for ssh. After so many minutes, I need to re-enter my PIN. That's not an Ansible issue.
--EbH