Replaced routers, added Pi-Hole as DNS - single machine gets DNS_PROBE_FINISHED_NXDOMAIN for certains sites

Question

Bit of info on the network.

1. Ziggo ConnectBox (modem/router) in bridge mode (this horror)
2. Linksys WRT32X (this one - 192.168.1.1) - primary DHCP, uses Pi-Hole for DNS (192.168.1.x static)
3. Linksys WRT32X (192.168.2.1, DHCP enabled, uses 192.168.1.1 as DNS)

Router 1 is downstairs, router 2 is upstairs.

---

So, that is, since today, the setup.

The problem, a single computer on router 2 has the issue that it gets "DNS_PROBE_FINISHED_NXDOMAIN" on certain domains. Seems to be specific to Facebook domains as it affects Facebook and Instragram. (Don't judge, not my pc...)

About the PC:

• standard Windows 1803 protection shizzle
• pretty much only things installed are browser (Chrome) and games via Steam/Origin

---

I've already tried a bunch of things:

• reset all flags via chrome://flags
• dump all cache/cookies in Chrome
• Change adapter DNS servers to Google's servers (also to 1.1.1.1 & 1.0.0.1 which the Pi-hole uses)
• ipconfig /flushdns (also as admin)
• netsh winsock reset
• Since Win10 1803 cannot reset DNS Service via services.msc (not even using psexec tool)
• Uninstall network adapter, reboot and re-install
• Other browsers on PC (IE11 & Edge)
• answer by Dennis below

(above list pretty much only solutions on first few google pages when searching variations of the issue)

But still... the missus cannot visit her FB/Insta 'whatevs' on that pc.

I'm hoping any of you got any idea of new things to try.

---

P.s. - asking here instead of network SE as it's a Windows pc (and no other computer/phone on the network has issues)

Answer 1

Here are some more commands to completely reset all things TCP/IP and DNS:

• Reset WINSOCK entries to installation defaults: netsh winsock reset catalog
• Reset TCP/IP stack to installation defaults: netsh int ip reset reset.log
• Flush DNS resolver cache: ipconfig /flushdns
• Renew DNS client registration and refresh DHCP leases: ipconfig /registerdns
• Flush routing table: route /f

After that you should reboot the machine.