How to remove or clear implicit A record

Is there a way to clear out the A record for a zone (i.e. dissociate IPv4)? I’d prefer to go IPv6-only.

The last time I tried it was sufficient to edit the zone (not the zone entries), clear the IPv4 field and save the changes.

I thought that would work too, but it seems to leave the address unchanged. Interestingly, there is an AAAA entry (under Resource Records) but no A record, so editing the zone seems to be the only place I could make changes to the IPv4.

I achieved this by deleting the zone and quickly re-creating it (which required generating new tokens).