I have an M4 Deco AC1200, (3 units). Everything works great, but once i connect a switch (netgear, linksys and TP Link) the light turns red and the wifi does not work, all the unites turn red.
If a i connect something like a computer to the second ethernet port on the M4 it works without any problem, but if i connect the switch to get more connections all the units stop working and the light turns red.
I have tried:
-Factory Reset on all units
- Change network cable (cat5, cat5e, cat6)
-Netgear switch (8 ports) gigabit (model GS108)
-Tp Link Switch (8 ports) gigabit (model TL-SG1008D)
-Linksys switch (8 ports) gigabit (model SE3008)
-Upgrade the firmware of the 3 M4 units to 1.4.3.
-After the upgrade i performed another factory reset to all the 3 units.
-Change the operation mode (Wireless Router & Access Point).
-Change all the decos one at the time to be the main deco.
The switches are working correctly. I connect them directly to my ISP modem/router and they work without any problem, but if i connect them to the Deco unit, all 3 units stop working and the lights turns red.