device not connected properly

Hello, I have 3 android phones exactly the same make/model all connected to my PC via USB cables with USB debugging enabled and I have premium paid account so I can use all 3 devices at once. Air mirror was working great over usb because the phones are not rooted for about a week but I woke up this morning and one phone was OFF but showing 100% charge, I thought OK and turned it on but now air mirror will not connect to this one phone. The little connecting box comes up in the middle of the screen and then it says "device not connected properly". I have tried:
Reboot phone, reboot PC
Turning off and on USB debugging
Revoking pc authorizations and then clicking the allow box when it comes up
Updating Airdroid PC app to latest
Unplugging the usb cable and trying different port
Verified MTP usb option is selected, changed to charge only and then back to MTP

I don't understand why the other 2 phones work just fine but this 1 phone will not air mirror. Do I have to have factory reset the device? It's about the only thing I haven't tried.

0 replies? I guess support for this product is non existent and they will just lose me as a paying customer when my premium expires. Another phone now has the same problem, if I am down to a single phone not only can I do this with a free account why would I pay for something that mysteriously stops working.
Ive gone as far as removing the software from Control Panel, then searching the registry and deleting all Airdroid entries and then went through the C: drive and deleted all airdroid files.

It baffles me that the problem still exists if basically the computer and the phone has been wiped, ive tried new cables and ports on the computer. Is the software just plain broken?