SOLVED: How do I play BFV on two PCs using a shared network?

EDIT:  SOLVED!  I solved this using Smart Port Forwarding, setting the Listen Port to 3659 for both UDP and TCP and leaving the Default forwarding path IP and Port at the defaults.  (I also changed the timeout period from 5 seconds to 10, but that is a personal preference and not related to the fix.)

Smart Port Forwarding can be found here: https://www.softpedia.com/get/Network-Tools/Misc-Networking-Tools/Smart-Port-Forwarding.shtml

Video instructions can be found here: https://www.youtube.com/watch?v=QMB4FTqziqw

I hope this helps someone!

ORIGINAL POST:
BFV will not allow me and another user to both play on the same server at the same time while using the same network.  Sometimes we can both connect to the server and make it to the spawn screen without the server disconnecting, but as soon as we are both spawned at the same time, the server disconnects us both with a message saying we lost the connection, even though we are both still connected to the server list - other times it disconnects us as soon as both of us are on the server together.  We can both play individually on separate servers at the same time.

We have no problem doing this on BF4.  Everything works fine other than a little lag sometimes.

We are connected to the internet via Wi-Fi to a phone, tethered to my PC via USB, and internet connection shared via ethernet from the first PC to the other PC.  Hardwiring to the modem is not an option, however that generally isn't a problem as this setup works fine for all our other internet and gaming needs; it is only BFV servers causing this issue.

I have looked this issue up and discovered this has been an ongoing issue specific to Battlefield games in general for the last seven years or more.  Of the many forum posts I read about this, the solutions offered do not seem to address the root cause of the issue and are generally not helpful for most users experiencing this, but once in a while someone is helped by them.

- I have already added all of the ports for both BF4 and BFV in the router.
- I have tried adding the +clientport 20000 and 20001 for each respective computer.
- I have not changed UPnP yet as there is conflicting information about this, some people say disabling it fixes it, others say UPnP must be enabled for multiple PCs to connect at the same time.  I'm not really sure UPnP has anything to do with it at all, frankly, as UPnP is generally not (ever to my knowledge) applied to connections with a login (i.e. a secured wireless connection).

What baffles me is that although this generally affects a variety of Battlefield games, and there are suggestions that router settings are responsible, my particular situation results in one Battlefield game working (4) and the other not (V) and only when both connected at the same time.  Seems very much like a server issue.

Are there any solid solutions after all these years, or is it a matter of blindly trying random things that don't seem related to the root of the problem?