Just got a message from G-portal saying that our server data was lost and that we can only recover our data if we saved it via ftp. Nobody played in a couple of days, so it was not our fault, best I can tell.
No further explanation, just "we lost your stuff". I sent a ticket to confirm that there was nothing else that they could do, they said no.
We did get a month of hosting free, but that's not great considering I have no confidence that my data will persist if I do anything without writing some script that backs up our stuff routinely. At which point.. I might as well just host it myself. (I pay for hosting to offload headaches like this)
Anyway, there you go. That's your warning. Back up your files.
Edit: on another note, anyone have recommendations for hosting services? I'm checking out dathost now.
Source: https://www.reddit.com/r/valheim/comments/sywnjx/if_you_host_with_gportal_back_up_your_stuff/