Samba share requires authentication when should not be requested

I have two shared folders: one unrestricted, and one allowed for a specific user.
After a random time (some hours, a few days after the router is on) the first folder becomes unaccessible, and the user is promped to input his credentials, after that it can be accessed.
What can I do to solve this annoying issue?

You'll likely need to look at the Samba log to determine what the issue is.

  • I can't recall what OpenWrt uses as the default location and log name (I utilize a custom /etc/samba/smb.config.template), but it should be in /tmp/log/ and can be garnished from the smb.config.template, or, if Samba is running, /etc/samba/smb.config
    • ls -s /tmp/log/ | grep smbd

It's also possible Samba could be restarting, which [likely] would prompt a user to re-login