The other miner are the same Avalon 1246 85th.
I have just check the network configuration and all look great.
I have also change the worker name with one of my friend and the problem still the same.
The only difference between the four asic is the firmware. The asic who not working have a different firmware of the three other since I have change the control board
Would you mind using a tool to check if your network and miners are set up properly?
You can use the Canaan tool called the FMS app you can download it here
https://canaan.io/service/447And diagnose the issue there if its a pool issue it is marked as red or if it's an IP issue it's the same marked as red same goes for other issues better use the manual on how to use the tool.
Also, try to reset your unit to the factory default you can hold the reset button or IPreport button for 10 seconds then release it to restore it to factory default.
If it still does not work try the aging process using the FMS tool to refresh this unit.
If nothing else works there might be an issue on the mac address and maybe one of the units has the same mac address it could also lead to a connection problem.