Expected Behaviour:
Pi hole shows the actual hostname or IP of the client making the query
Actual Behaviour:
Most queries show as coming from vodafone.broadband (my router's hostname), except two laptops which show their hostname
Edit: I also have this in the log, maybe it's related?
Jun 30 22:02:23 dnsmasq-dhcp[28388]: no address range available for DHCPv6 request via wlan0
Further edit: i disabled ipv6 as I don't think my ISP's router supports it (Vodafone UK).
For example, I have a tp-link access point that I know is continuously pinging tp-link.com, but pihole shows the query still coming from the router
Debug Token:
https://tricorder.pi-hole.net/ofi1ilob95
That expectation would be justified if you were distributing your Pi-hole machine's IP address via DHCP, to be used by your clients as local DNS server.
If you had configured your router to use Pi-hole as its upstream DNS, all queries would originate from your router.
See also Pi-hole's documentation on Making your network take advantage of Pi-hole.
I'm using my pihole as DHCP server and configured my router to use it both as DHCP and DNS. There is no distinction between local/upstream DNS setting in the router UI but I believe what I am setting is the local DNS. I followed method 1 in the link you posted. Not sure what I am missing and whether it can be seen from the debug log?
EDIT: here's my router log if that helps https://pastebin.com/7BrBfiR4
If you've setup Pi-hole only recently, your clients may still hold on to their DHCP lease information, until those leases would expire eventually.
Lease times vary with routers, they may range anywhere from hours to weeks.
Since Pi-hole is acting as DHCP server in your case, it will distribute itself as local DNS server, so there is less reason to tweak DNS settings in your router.
Your observation would make perfectly sense if you'd had configured your router to use Pi-hole as upstream (commonly, a WAN/Internet setting, whereas local DNS servers show up as LAN/DHCP setting):
Clients holding on to their leases would send DNS queries to your router, and your router would forward them to upsteam Pi-hole.
If you do not want to wait for leases to expire, you could force your clients to renew leases by disconnecting and reconnecting them to your network or by power-cycling them.