CAA requests resulting in SERVFAIL since Dec 12th

Slightly hijacking the thread but it looks like DNS services provided by (tucows) currently return an acceptable response for the primary domain but forget to include SOA records in some subdomain responses e.g. www, but not all. The nameservers affected are and

I'll see if the affected user is willing to share one of the domains here as an example.

It may depend on other config like whether they have an existing A record or whether they're using a catch all to direct all subdomains to an IP