I need help with windows 10 remote assistance

I could really use some help.  I have set up 4 PCs in different locations with Windows 10 and need to be able to use remote assistance to help the users.  Each of these builds are clean, with a fresh version of Norton (either retail or a Comcast version).

Remote assistance works within the LAN at any of the 4 locations, however, my issue is I cannot connect remote assistance from outside the LAN (over the internet).

I am confident this is a Norton issue based on the fact if I disable the "Smart Firewall" I am able to connect the remote assistance from the internet.  Also, I can create a top level firewall rule that allows all incoming and outgoing traffic to all ports and this also works (however this defeats the purpose of having a firewall).

The only thing I could come up with was changing the Network Trust to "Full Trust" but this did not correct the problem.

I attempted to use the online chat support (Ticket No.25389162) but after an hour online it was clear that the support rep was not going to be able to help.

I could really use any insight anyone has on this topic.  Thanks in advance.

Bill