PROBLEM SOLVED - THANK YOU!
I rebooted my modem, router & ISY controller. I then rebooted my computer, then dialed the Kaspersky firewall, and then successfully set up the device using Link Management - Link INSTEON Device functionality.
It is not clear to me if the fix was rebooting the ISY controller, disabling the firewall, rebooting the other equipment, or maybe something else. Nonetheless, the issue has been corrected and I appreciate your help.