Dovecot dh.pem warning after ISPConfig install

After I update ISPConfig I get the following warnings from Dovecot:

dovecot: config: Warning: please set ssl_dh=</etc/dovecot/dh.pem
dovecot: config: Warning: You can generate it with: dd if=/var/lib/dovecot/ssl-parameters.dat bs=1 skip=88 | openssl dhparam -inform der > /etc/dovecot/dh.pem

I fix it myself everytime after an update. IMO the ISPConfig installer should generate the dh.pem if it doesn't exist and add the ssl_dh line to the dovecot config.

Environment: Ubuntu 20.04, ISPConfig 3.2b3, coming from the first nightly and have updated to every new beta since.