Hello, I'm looking for advice if I have a fault device.

I just purchased a "manufacturer refurbished" TL-WPA7617KIT from Target with the objective of getting a handful of smarthome devices in the bedroom a strong enough wifi signal to stop frequently disconnecting—they don't need fast speeds as they arne't doing much.

Surprisingly the devices arived in a generic brown box (e.g. no packaging) without any bubble wrap (not very protected). My guess is this is probably a return from target and not a true refurbished unit.

The device worked well for two days and was exposed to our typical powerline usage (e.g. ACs turning on in one room durring the day and another room at night). On the third day the device wouldn't connect to the main hub all day. When unplogged and pluged back in the home icon would blink on and off for one second. Nothing changed in our apartment and no new devices turned on or plugged in.

After a day I did a full reset and plugged it back in and it reconnected to the hub immediately. Again it worked well for two days and then stopped working for an extended period of time.  In the course of both of these disconnects nothing significant has changed without our powerlines. I did orignally have a scheduled power off on, but now have removed it.

Is this machine acting faulty? Or is my powerline the issue? 

Is there anything else I can do? I've already removed one of the wifi bands (following advice on this forum) and removed the scheduled power off.

Thank you.