[Koha] overdue_notives - to_address field is not populated

[ISM KIS]

After upgrading to  Koha 3.4.5 we have noticed that the overdue notices were not sent.

The cron jobs are running and the message_queue table gets updated.
The borrowernumber is correct  in the message_queue but the to_address field is NULL.
( select email from borrowers where borrowernumber = xxx  gives me the correct email)

Any ideas why the to_address field is NULL and what to do about this?

If I manually update the to_address and run process_message_queue.pl then the notices are sent ok.

Thanks for any help.

Rudy Wuthrich
Kodaikanal International School