Can't map drive between PC and Virtual Private Server

A few days ago I acquired a Virtual Private Server through Atlantic.net.  I configured it to run Windows Server 2012 R2 so that I can run a Microsoft Access database on it which two other people can access and use.  Everything worked fine until I got to the last step which is mapping a drive to the VPS on my home computer so that I can more easily update the Access database file on the VPS.  Home computer is running Windows 10 Pro, and I also have a laptop running Windows 8.1 Pro, but neither one will map a drive to the VPS.  I get an error saying "Network error.  Windows cannot access XX.XX.XX.XX.   Check the spelling of the name.  Otherwise, there might be a problem with your network."  I get the same error on both home computers.

So I called Atlantic.net and spent almost 2 hours on the phone with them trying to resolve the problem.  We double-checked all the required settings on the VPS and my two computers, and all was configured correctly, including Firewall rules.  Then the tech support guy tried to map a drive to my VPS from a computer in his office which is outside their own network, and it mapped a drive without any problem.  They concluded that something in my router is preventing me from mapping a drive to the VPS.   I don't know where to even begin looking for settings to change, and I can't find any info about this online or in the Netgear KB, but it is definitely something related to my router.

This morning I tried mapping a drive to the VPS from a computer in the office where I volunteer, and it mapped the drive without any problems.

I can RDC into the VPS without issue.  It is just mapping a drive that fails to work.

Both my computers and the VPS are configured to have file and print sharing turned on, and all the relevant services are running.  We set up an SMB Inbound rule on the VPS to allow access through ports 135 and 445.  Yet I still cannot map a drive to the VPS.

Tech support thought the problem might be resolved by configuring DMZ on the router, but this is not something I am familiar with.  Can anyone advise me on how to proceed?