powerline adapter/network issues

Hello,

I just bought a new powerline adapter (tp-link av2000) in order to connect our network to a basement and am having bizarre issues. The configuration is as follows:
1. Cable Modem acting as a gateway ->
2. Server/router running pfsense (WAN)...also a LAN feed to ->
3. Dell 8 port gb switch
4. From switch, connections to
a. desktop pc
b. older, pre-existing powerline adapter that feeds a desktop in another room (no issues here)
c. wireless ap
d. newly purchased powerline adapter (tp-link) that feeds a few computers in the basement
Everything works fine (except of course the computers in the basement) without the new powerline adapter plugged in (4d). Once I plug this in, everything works fine, including being able to access the network and internet from computers in the basement. But, after about 2-5min., the network freezes up and I can no longer ping any machines on the network and the internet does not work. I tried many different combinations to no avail. Once I unplug the new powerline adapter, everything is back to working almost instantly.Does anybody have any ideas what might be going on?

Please help

I didn't find the right solution from the internet.

References:
powerline adapter/network issues - Ars Technica OpenForum
Motion graphics video animation company

Thank you