Backup network folder unreachable overnight

Hello!

After more than a year being able to create EmbassyBackups seamlessly from my StartOS server to a network folder on my QnapNAS, suddenly it stopped working. It appears my server no longer recognizes the network folder. I’ve changed nothing (same SMB versión, same credentials, same path, etc.). It keeps showing RPC ERROR: Mount error: No such file or directory.

I’m able to ping the NAS but couldn’t mount the folder via CLI (neither SMB nor NFS work) as it also shows me the same mount error. I’m quite a bit lost here and can’t figure out where the problem could be.

I’ve been trying subnet routing with Tailscale (which I’m aware can cause some networking funny things), but I’ve already disabled it, restarted devices and services, and keep getting the same issue over and over.

I will much appreciate help here! Thanks!

What’s the relationship between Tailscale, and the QnapNAS. Did you configure the QnapNAS to be reachable over the tailnet?