Firmware Tool "Could not connect to the update server!"

[Stephen Betts]

I finally managed to get one on my devices working on one of the newer releases 1.20.2.r4 after being stuck at 1.20.1
I realised you had to clear the flash etc in the upgrade page otherwise you get a flashing red light and no command prompt in pymakr / vscode

today I tried to update another one but i get the message
"Could not connect to the update server!"

whats causing this ? isthe server down , the DNS entry it queries seems to be valid
Re-downloaded 1.16.5 just incase but still the same

Tried the direct download page, but cant seem to see that image listed
https://software.pycom.io/downloads/LoPy4.html

Also what is with the naming scheme
.b beta ?
.r release ?
.rc release candidate
what are development releases ?

the standard ESP32 offers daily release I can see what they are doing with pycom it seems to be very difficult, no change log, and i find myself going around in circles

What firmware should you use, don't want to be bleeding edge, but want something that works