You may try as it won't take too much time...

Are they running in latest firmware? What's the hardware version? No one reset them but they lost settings by themselves?

Check firmware version of your WA850RE and ensure it is the latest version, otherwise, upgrade its firmware. http://uk.tp-link.com/support/download/?model=TL-WA850RE&version=V1#tbl_j Reconfigure the...

To figure out Wi-Fi range is normal or not, you should test by another wireless client in the same location of WN722 to compare the range. The adapter has no internal antenna and it should work with...

What's the operating system of your PC installed WDN3200? If you disable Wi-Fi security on the router, does it connect to 5GHz Wi-Fi successfully? What's the model number of your router?

The problem you mentioned sounds quite abnormal and I've never heard of it before. Have you tried different power sockets for the PC and W8960? If the computer is off all the time, W8960 will be...