My mobile internet provider doesn’t like the Blynk’s binary login protocol TCP PSH packet login packets! (but is OK with HTTP to ports 80 and 8080)
OK I setup my own blynk server and tried to connect to it from the WAN with the tethered WIFI smartphone.
Result: atfer the TCP 3-way handshake, the ESP nornally sends a PSH-flagged packet to the Blynk server with the Auth token as payload, which I assume is the login from the hardware to the server.
When I do this via the tethered smartphone wifi, either: the packet never leaves the ESP, or it leaves and is dropped/lost by the mobile ISP (ISP Firwall?), Anyway, that kills the TCP connection as my ESP send a FIN after waiting around 10 seconds.
So yes I think it maybe time to try another mobile ISP/SIM.
Or… is there another way to login to Blynk-cloud perhaps?