Try to move the powerline unit closer to see whether it can get stable connection. If the issue still exits, it's better to send email to tp-link support for further help.

Have you tried different USB port the computer? Generally speaking, channel 132 should be visiable because it belongs to band 3 which is supported by T2UH.

Try to change the wireless channel on your router. If still no success, reinstall the latest driver on the computer. Good luck..

If you don't know how to change wireless channel on your router, it's better to contact your router's support to help you. After you change the channel, try to restart the router and range extender....

Try to hard reset the router by pressing the reset button on the router for 15s to hard reset. After that, power it off and on to restart . Good luck..

flying snow may mean you should contact tp-link support via hotline directly. Afterall, it seems it's hardware issue and we don't need to bother to fix it.