I have a home network made up with a LINKSYS E2500 router (net SSID: LINKSYSWF1). To it I connected a TP-LINK 7055 POWERLINE CENTRAL UNIT via ethernet cable.
On the AC network I have two POWERLINE ADAPTERS - 1) TP-LINK 8955 broadcasting net TPNET1, and 2) TP-LINK 9400 broadcasting net TPNET2.
I connect to this networks a makeshift desktop pc with an ASUS mother, and a SAMSUNG NOTEBOOK with a USB TP-LINK TL-WN823N adapter.
So, from both pc's I can see 3 WIFI nets, LINKSYSWF1, TPNET1 & TPNET2.
Recently, the SAMSUNG notebook stopped seeing the TPNET2 WIFI net. It just dissapeared. It still sees LINKSYSWF1 & TPNET1, and several other wifi networks of neighbours, etc.
The ASUS still sees all three. Actully, it connects to TPNET2.
I removed th TP-LINK USB adapter and plugged in another identical one, same thing. I removed the USB adapter and uninstalled the TPLINK controller, rebooted and re installed everything. TPNET2 is still invisible.
I removed the adapter and uninstalled the controller. After that, I removed manually all references to the POWERLINE adapters and TPNET1 and TPNET2 from the registry. I also checked the firewall and the antivirus program.
I re-installed the USB adapter and the TPLINK controller. Nothing. Still the SAMSUNG notebook does not see the TPNET2 WIFI from the TP-LINK 9400 adapter. It does see all other wifi networks.

9400 DATA:
WIFI AV600
MODEL TL-WPA4220 (AR) VER. 3.0
FIRMWARE: 1.3.0.2134-00_401091_160311_906

¿Any clues? Anyone will be most welcome. thanks.