SAME MAC Addresses (LAN & WAN) for Two MN-700 Base Stations

Here is my problem

I bought 2 base stations (MN-700), 1 to serve as a router
(first floor) and the other to serve as an access point
(basement), no problem at all, until I interchanged the
units, put the basement one on the firts floor and the
other in the basemente, I used the saved settings from
the first one to change the second base station to router
mode, and manually changed the first one to access point.

After that I began to have problems with intermitent
connections to the internet, after a lot of research, I
found the problem, both base stations have the same MAC
addresses (LAN & WAN), I changed the WAN Addresses with
the clone option to the ones in the sticker of each base
station (so now I have 2 "normal" different MAC Addresses
for WAN interfaces and 2 "irregular" equal MACs for LAN),
I cannot change the LAN addresses, so I continue to have
the same problem, even when resseting to factory defaults
the MACs remain the same, is there a way to change the
MAC addresses for the LAN sides? anyone?