local stanza only generated for IPv6

I have a mail server with multiple IP addresses and associated DNS names

In the dovecot configuration I have a listen directive:

    listen = mail.example.com.com,mail.otherexample.com,localhost

Multiple local stanzas are of the form:

local mail.example.com { protocol imap { ssl_cert =

     service imaps_login { inet_listener imaps { address=mail.example.com } inet_listener imap { address=mail.example.com } } } }

mail.example.com has IPv4 and IPv6 addresses in DNS

When I run doveconf -n the local configuration is only generated for the IPv6 address. I can test the operation on IPv6 using openSSL and see different server certificates on different IP addresses as expected.

How do I force local generation for both IPv4 and IPv6 ?