exchange hybrid setup problem with inactive mailbox in mailcow

I have a problem with Exchange Hybrid Setup - mailcow: dockerized documentation

docs.mailcow.email

Exchange Hybrid Setup - mailcow: dockerized documentation

None

in exchange: user1@example.com (active)
in mailcow: user1@example.com (inactive) and user2@example.com (active)

user1 (exchange) can send emails to user2
but user2 cannot send email to user1 with this error:

user1@example.com: host dovecot[...] said: 550 5.1.1
user1@example.com User doesn’t exist: user1@example.com (in reply to RCPT TO command)

I expect that user2 can send email to user1 (exchange) as long as user1 (mailcow) is inactive and “Relay non-existing mailboxes only” is checked for example.com