error when enabling tlsa via the command-line

When I modify dns for a domain by executing via the commandline:

virtualmin modify-dns --domain <domain.tld> --enable-tlsa

the job seems to get done but there is an errror given in

virtualmin modify-dns --domain <domain.tld> --enable-tlsa

Updating server <domain.tld> …
Creating TLSA records …
… done

Can’t use an undefined value as an ARRAY reference at /usr/share/webmin/bind8/ line 439.

The domain is properly configured to use DNSSEC (see:

The error seems to be related to the serial of the domain but after the command the number is bumped to a higher value.

The zone itself seems very straightforward with some NS, A, AAAA, CNAME, TXT and MX records (and of course the DNSSEC related records).

Is this a bug or …

Any help is appreciated.

Anyone familiar with this error?