Can’t map a drive

I have a multihome server.

eg. 192.168.x.x and 204.50.x.x

1st ip address on the server is 192.168.x.x

My PC’s IP address is 192.168.x.x

I can map a drive to \\192.168.x.x\sales but I can’t map the same share drive from
\\204.50.x.x\sales.

Why I can’t do this? What am I missing here?