Unfortunately, the way operating systems are set up to prefer IPv4, and the spammer-banning techniques availablem there is a possibility that legitimate users will be caught up in temporary automatic spam-handling methods.
To turn these off would mean more work than moderators could handle.
I haven't found any options to suggest browsers prefer IPv6 - if your internet providers even support it.
Between this, and temporary outages / blocks that are complete out of my control - the only way I can help is if the site is down for everyone. My apologies.
There is, theoretically, a way to force IPv6 - hosts file entries. I'M PUTTING THIS HERE FOR MY OWN NOTES, YOU PROBABLY DON'T WANT TO DO THIS
Unfortunately my ISP turned off their tunnel broker, so I'd need to get an IPV6 capable router before being able to use IPV6 myself, and my telephone company doesn't support IPV6 for mobile data either.
It's probably just as difficult if not more difficult for others.