Probably the devices on WiFi dont have a route to the wired devices or the router blocking traffic between the two.
Can you ping Pi-hole, which I presume is wired , from a Windows PC connected via Wifi ?
A traceroute from the Windows client ?
tracert <PIHOLE_IP_ADDRESS>
If you router doesnt allow traffic between the two network segments, another option is to connect Pi-hole to both wired and WiFi.
If the wired and Wifi clients are in different subnets, assign appropriate IP's to the two interfaces and configure the "Interface listening behavior" setting to "Listen on all interfaces" below:
http://pi.hole/admin/settings.php?tab=dns
If they are in the same subnet, best to add/create a bridge interface named br0 with an IP in the subnet, add the two physical interfaces (without IP) to the bridge and reconfigure Pi-hole to listen to the new bridge interface.
For a bridge, put below in the "/etc/network/interfaces" file (your interface names could be different!).
And you might need want to install 'sudo apt install bridge-utils'.
auto lo
iface lo inet loopback
iface eth0 inet manual
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
auto br0
iface br0 inet manual
bridge_ports eth0 wlan0
bridge_stp no
Put your WiFi details in the file "/etc/wpa_supplicant/wpa_supplicant.conf" like below.
Change country or some Wifi channels might not be available (local laws might restrict channels).
And oc put your own SSID and pass in the file:
country=NL
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="YOUR_WIFI_SSID"
psk="PASSWORD_FOR_WIFI"
}
Set proper ownership and permissions:
sudo chown root:root /etc/wpa_supplicant/wpa_supplicant.conf
sudo chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf
And configure IP for the bridge interface at the bottom in the file "/etc/dhcpcd.conf" (watch for duplicate entries!):
interface eth0
nodhcp
nodhcp6
interface wlan0
nodhcp
nodhcp6
interface br0
static ip_address=<PIHOLE_IP_ADDRESS>/24 # Change 24 mask if other!
static routers=<YOUR_ROUTER_IP>
static domain_name_servers=127.0.0.1
Reboot to apply/test:
journalctl -u networking
journalctl -u dhcpcd
ip l
ip a
ip r
sudo brctl show
To reconfigure Pi-hole, run below and select reconfigure:
pihole -r
EDIT: added some