If you have a TPLink Range Extender or Access Point which your windows device can't connect to the 5Ghz band, try this. Worked for my RE200 v2

Try changing the encryption from "Auto" to whatever your main router is using, in my case "AES", then reboot the TPLink, remove the WIFI network (SSID) from your laptop, then re-add the WIFI network (SSID) and connect. The removal/re-add of the SSID might not be needed, but it was one of the steps I performed when I resolved the issue. All the other tweaking and tinkering didn't do anything.