I'm not sure someone here will have an answer. I've done some googling from time to time and haven't found a reason/solution. My Macbook Pro shares a folder. I'm on multiple networks most with Windows Server running DHCP and DNS.
When I go into System Preferences - Sharing, the name the system is reporting files can be accessed shows a name of a different computer on the network which isn't the name of my Mac. This only seems to happen in Windows Domains with MS DHCP/DNS running. When I look at DHCP I see the name of my Mac with the IP that I have.