Problem with Range extender

I have a TP-Link WA850RE and I have a problem that seems to happen consistently.

For some reason my repeater seems to lose it's signal even though it shows I'm at 3 bars which is decent according to the manual.
The only solution I've found to fix this problem is to unplug the device or restore the thing to it's factory settings.
What is the problem and why is this happening? This problem has been happening since it came out the box and it's giving me a headache.

This sounds more like a problem for TP-Link people to answer.