Update: nmap -p N 10.0.0.2 reports that both ports are open, where N = {5001, 5002}.  Thus, I suspect the forward DNS is firewalled.  I had this problem when I setup SSH, I could only logon outside my home network by using IPv6.  However, I have tried to configure electrumX with IPv6 and that did not work at the time, but I may have changed reconfigured other options since.  I will retry IPv6.