Well here's the last one I can think of tonight, brain starting to shutdown LOL.
Create a new share named test (all lowercase).
Enable permissions, make guest read-only and admin read/write.
after applying changes, reboot the LS pro duo (maintenance tab i believe). When it comes back up, validate it's IP address is still current and and try to map the test share.
If that works, then try the share share.
Reboot will restart the daemons/services on the device, and making a new share will cause it to update it's permissions.
Outside of that, I'm clueless. using the correct IPs etc, I can't cause that to happen unless I add a firewall to the mix, but doesn't sound like you've changed anything.