I have been using several WPA4220s on my LAN for many months without issue. A few days ago they all stopped working and won't pair (I get no flashing led when trying to). Uploaded the latest firmware on one of them, still won't pair.

I have a PA4010 on the network which still works fine.

Tried resetting everything to no avail.

Get three leds on the host unit as normal, power led flashes when in pairing mode as normal.

Anyone any ideas?