It would help if you did inform us if you host your own dns server on your Virtualmin or If you had to copy and paste it to another provider.
Reason is most DNS providers don’t allow the " " syntax. Some will try to automatically remove them and not do a good job at it. As where BIND DNS allows them.
If this is the case? You need to make sure that all the " " (quotes) are removed along with any spaces.
Inside the key itself.