I do not own my own IP address. And this blog is not being hosted from an IP address I own, but rather from a personal IPv4 address owned by my ISP, which they allot me via standard DHCP protocol. Hence, my ISP is free to change my IP address, and to assign me a new one at any time, on the assumption that I only have an account for personal use.
When the ISP does this, I have software in place, that makes sure my domain names still resolve to the new IPv4 address, i.e. software which updates the DNS servers with my new address. I am a client of DynDNS.
But since last evening, there has been some unusual activity in this regard, in that my ISP did not only assign me a new IPv4 address, but did so roughly once per hour, until today.
While doing so only disrupted IPv4 access to my blog minimally, it did in fact disrupt IPv6 access to my blog. Right now I have updated my IPv6 address again manually, so that IPv6 access should be possible again.
But I do hope that this malfunction has now passed.