No psql md5 auth, psql 14.1 to PG 11

I'm unable to authenticate with psql to a PG 11 database on server A from
server B which has PG 14.1 installed. So it's psql 14.1 not authenticating
to PG 11. Other clients can and do authenticate to the PG 11 database, it
only seems to fail with the psql 14.1 client.

The PG 11 server uses md5. So is the PG 14.1, but I didn't expect that to
matter for a straight psql connection plus interactive password entry.

The error is "fe_sendauth: error sending password authentication".

The bigger picture is that I'm trying to set up a FDW connection from
Server B's PG 14.1 back to Server A's PG 11. I hit this same error and
shifted to troubleshooting with just psql but kept getting the error.

I've checked for md5 use on both servers, but I still don't see a role for
that with psql on Server B's psql.

What can I do to get authentication working?

Thanks,
Pete O'Such