I know that this is an old post, but I write down the solution I founded for future users.
I had the same issue: it works fine unless I activate the wifi extender, thus the camera disconnects from wifi (led turn red).
I have macaddress check active on my router: deactivating macaddress checking cause the camera works fine.
As a consequence, I check the camera mac addres (by arp -a) both with extender turned on and off: the mac address change!
The solution was to put both the mac addresses as valid in router mac check.
Hope this help.