I had to take backup off-server to a network location. So, created a job tried running manually; it ran just fine. I scheduled the job check during the run time, it fail! Job history
(
showed the \ did not have permission on the location. Gave the domain user full access to the location, still did not work. I check the user under which the SQL Server (InstanceName) service was running, it was a different domain user; once this domain user had FULL CONTROL to the network location, the job started backing up in a network location specified by UNC.
Here is a reference: Microsoft Article
Hope this help someone.
astu...