postgres 11 issue?

I've just updated my laptop to pg11 and I'm getting a problem. I'm  trying to
keeps the details confidential, so somewhat vague I'm afraid.

sjr_local1db=> select count(*) from user_passwords ;
ERROR:  record type has not been registered

sjr_local1db=> insert into user_passwords (name, "timestamp", password) values
('user1', my_timestamp_now(), 'dsfsdfsdf');
INSERT 0 1

sjr_local1db=> select count(*) from user_passwords ;

 count
-------
    27
(1 row)

The timestamp column is a "row" consisting of a timestamp and the timezone
(essentially),  the my_timestamp_now  is function that returns a "timestamp"
for now. 

This all works fine for pg >= 9 and pg <11.

Steve