IPv6 Range on Rocky Linux

OS type and version: Rocky Linux 8 x86_64
Webmin version: 1.981
Virtualmin version: 6.16

I’ve just spun up a new server on Rocky Linux and installed virtualmin. I am unable to add IPv6 Addresses from a range assigned by my host. Error message when trying to allocate an IPv6 Address from the range is:

.. IPv6 address failed! : Failed to add IPv6 address : SIOCSIFADDR: File exists

I have added the range in the System Settings → Server Templates area.