This might a simple option that I'm not sure where to turn on. My WS2003 VM is not able to access/browse the shares on the host machine which is a WS2019. The VM is a domain member. I get the error message:
\\SERVERNAME is not accessible. You might not have permission to use this network resource.
I can browse other machines with folder shares on the network from the WS2003 VM. I'm logged in as Administrator on the WS2003 VM while trying this out.