Block storage works finally
No idea what was wrong, they told me to do some stuff, and it’s finally working. Already switched /home to the block storage, and there’s a backup partition too.
I wonder if I did one thing they said to do, it would have fixed it without emailing them.
If your BuyVM block storage isn’t working, try shutting it down, detaching the block storage, then attach it, and try booting. No idea if they did something on their end. If that doesn’t work, you’ll have to open a ticket.