Note that when you restore on IP2, Cloudron will adjust the DNS of the apps to point to IP2. It can do this only if you use one of the programmatic DNS providers. If you use manual/wildcard DNS provider, you have to change the IP manually yourself.
Having to go through a restore, this was baffling with no hints for me too.
I'll make a Feature Request to make this more obvious in the restore dialogue.
@ethanxrosen if you have backups, this will be in the box_<version> filename portion. Otherwise, if you have access to the server, it is at /home/yellowtent/box/VERSION
@gerard thanks for testing. A fix for this is coming next release.
The issue is fairly recent. SpamHaus made some policy change when requests come from IPv6 addresses.