(Sure would be nice if I could post this on GrapheneOS’s unofficial sublem, but anyway . . . )
Using Graphene, I made a local Seedvault backup on my phone that I would like to upload to the cloud, specifically with/to Filen, but I can’t seem to do this, and I’m not aware of any of my other files having this issue. Is this a permissions issue with Seedvault, or is there something else going on?
Seedvault is half broken and isn’t supported. They’re planning on replacing it with something better, eventually.
Meanwhile, you might get better answers from their own forums. Personally, I just use USB.