It's most likely called AP isolation. You can find it in Advanced > System Tools > System Parameters > AP Isolation. My Chromecast wont work if it's enabled either, because it basically blocks wifi...

Archer C1200 .. It's dirt cheap but it delivers.

I'll bet my left nut that it isn't the router, but rather Windows causing issues. I had this issue as well. Try this; 1) Open the command prompt (cmd) as admin and type netsh winsock reset catalog -...

ShieldsUP! by Steve Gibson. https://www.grc.com/x/ne.dll?bh0bkyd2

Testing my routers firewall today and it seems whenever it's set to optain time automatically, port 123 is closed (a.k.a. actively responding to requests) instead of NOT responing to requests. I'm...

I've used the TL-SG1005D for years and it has worked aboslutely flawless from day one. This is during heavy use as well.