The ECONNRESET error was only posted once before on the forum in a searchable way, which was here
Probably unrelated and there was no UPnP success in this case either. But something seems to be resetting the connection in either case. As it was related to the great firewall in the Chinese case, I was wondering about this in the current case:
I would recommend that @Gaetan_Patenaude turns this temporarily off for testing. If that helps, he’ll have to configure exceptions for Roon, probably. (The Core is on this MacBook where this ESET firewall is running, as far as I understood)
The Videotron manual I copied above seems to say that their router IP is 10.0.0.1
which would be consistent with the OP’s
“upnp_autoconfig”: {“server_ip”:“10.0.0.1”,“found_upnp”:true}
and looks OK