Problems with EX7000 Wifi range extender

Hi

i bought two of the product from amazon, when I got them I installed each one near the router and all was fine (both of them recognized quality of 82% near the router in both bands)

it working well for few hours (all the lights are green) and then it is starting doing the problems.

Sometimes the light are off, sometimes they become orange and sometimes red lights.

i don't know what the problem I also connect an internet cable the each device directly from the router to make better quality and connection.

Also the signal of the wifi is not the best, even not far away from the extender, what can to be the problem?

i bought two to connect two devices to make the perfect wifi signal in my house

Please help me solve this problems.

Thank you!!