Take a look here:
There are links to 3 different programs to set a unique MAC address on each radio. Disconnect all but one, powercycle, and then update unit #1, disconnect. Then modify unit #2 to a different MAC, and then you can choose if unit #3 stays stock or if you also make that different as well. I would set all three so you know they are all unique.
Since the MAC addresses are all different, DHCP should then assign new and unique IPs to all three units.
With a MAC address collision your network did not know which switch port to send the traffic, and that's why it kept dropping.
73, KD7HGL
Josh