Time Machine and AFP have stopped working. I think it may have happened at the firmware update before last but cannot confirm that. I have an HS-251+ w/ firmware version 4.3.6.0959 I have macOS 10.14.5 and QNAP.
When I try connect to the NAS using Finder (Go > Connect to Server > "afp://NAS1" > Connect) I receive an error: "There was a problem connecting to the server NAS1. The server may not exist or is not available. ...etc" I can no longer see the server in Finder side panel, but if I click Network I can see it only if I turn on Windows Networking. On a linux workstation I can see all the NFS mounts fine.
Time Machine can no longer find NAS1 to back up either.
I am completely stumped as to how to fix this.
Thanks
Bryon
QNAP Support confirmed this is a bug. I was able to confirm that it only happens if you create additional shares - then time Machine stops working. You delete the shares and time machine can see the Nas again.