No known issues. TP-LINK's official driver is also provided by Atheros, but now Atheros release a newer driver. As the problem occurs after system update, I think the new driver worth a try....

https://www.atheros.cz/atheros-wireless-download.php?chipset=65&system=8 For windows 8.1 x64. Official driver from Atheros

You may have changed the login IP before. Connect your computer to the TP-LINK router. Check the IP address and gateway on your computer. The gateway address is the current login address. If you...

TP-LINK routers (and other routers) allow Ping packets coming through by default.. I think you can enable DMZ for your computer. Forwarding -> DMZ --> type in the IP address of your computer. Better...

1. Maybe someone lingers in your Wi-Fi and using the bandwidth. Change the WI-Fi password. 2. Maybe some background programs on your devices are downloading and eat up the bandwidth

internet ---- Cisco router ------WR642 ---- computer In your topology, the computer has to get through two routers (2 NAT), of course there will be speed loss. Change your usage, follow this article...