I put a 2nd router in a DMZ after the ISP provided router, and my household is now behind the 2nd router (using the firewall in the 2nd router). If I run the automated SG Security Scan that cycles through the ports, it shows hundreds of open TCP ports, but when I test several of the purported open TCP ports via scanning a single port at a time (type them in), they show up as filtered. What is the issue w/ this inconsistency in the results?