hey, since your hardware version is V4.21, you can only update the FW of V4. We can't upgrade with differnent hardware versions.

did you try any other devices? If it can't charge any device, it may be dead.

hey, have you changed other fixed wireless channel? Try to change another channel firstly.

If you pair them seperately, they are two differnent powerline networks. We need to pair them with a pair firstly. Then, try to add third, fouth one by one. Have you tried this? you can have a try:...

what's the HW and FW of your MR200? Do you update to the latest FW? You mean you disconnect LAN cable, it will switch normally;however, disconnect provider's router, it won't? The LAN cable is used...

Thanks for your sharing. Such a big project.