Setup help pihole and tp link router, some devices no internet.

[deHakkelaar]

EDIT: I was just to post below @jfb

Setup router as described in below FAQ (methods 1 or 2):

How do I configure my devices to use Pi-hole as their DNS server?

Three methods Generally, there are three different methods that will enable devices on your network to be protected by Pi-hole. 1. Define Pi-hole's IP address as the only DNS entry in the router Rationale Only is italicized here for a reason: Pi-hole needs to be the only DNS server because it intercepts queries and decides whether or not they should be blocked. If you have other DNS servers configured, you may be sent to the correct domain, bypassing Pi-hole completely. Because of this, we re…

Disconnect client(s) from network and reconnect.
Check what DNS server(s) is/are assigned to the clients via the router DHCP service.
On Linux/MacOS clients run below:

cat /etc/resolv.conf

Or if Linux network-manager is installed, check profiles:

nmcli connection show --active

nmcli connection show <UUID> | grep -i dns

Or on Windows clients:

ipconfig /all | findstr "Server"

Or on Android clients if have the "Terminal Emulator" app installed:

getprop net.dns1

getprop net.dns2

getprop net.dns3

Only one DNS server IP should be configured on the clients, the Pi-hole IP address.
If any others are listed, ads will leak through via those other DNS servers.