Dynamic DNS vpnXXXX.softether.net points to old offline IPv6 Address, how to delete entry?

[pedrombfer]

Here is the situation:
We had softether on the "old server", and that server had IPv6, so the domain vpnXXXX.softether.net gained an AAAA record pointing to the IPv6 address.
But now, we migrated SoftEther to a new server without IPv6, however, the old AAAA record remains, making vpnXXXX.softether.net point to the old IPv6 address...
How can we delete this entry?

We have the DNS Key... is there any way to use some sort of terminal command to force a re-write/deletion of the AAAA record?
Thanks in advance