I have a TL-WPA4220KIT that had been operating fairly satisfactory since I installed it -- except for the occasional dropping of Internet, that needed to be restarted either by unplugging one of the two adapters or -- when that failed -- resetting my modem.   There is nothing connected to the adapter that feeds from my modem, and on the other side, there is a Windows10 laptop and a gaming machine, both connected to the RJ45 ports.  Additionally, wireless is on and usually my iPhone is connected to it.  

Occasionally, either the laptop or the gaming machine are on together, but usually it's either one or the other, although both are connected.  This has never been a problem until today.  Spontaneously, it seems, for no apparent reason because there have been no physical alterations to this configuration, if I boot up one of the machines while the other is physically connected, whether on or off, after connecting to Internet, after about a minute, internet connectivity is lost on the RJ45 ports and wireless.  

This only affects the remote adapter.  If I connect a device to the adapter running into the modem, it maintains its connection to the Internet and, using tlplc.exe, sees both adapters.

Any ideas?