Router ignores static DNS setting

[nightcustard]

Hi
I'm at day 2 with my new 8900AX2400 and am struggling with DNS - I've loaded firmware 2.52.d12.
I have a PiHole server on the LAN that I wish to redirect DNS queries to, so under Advanced Setup/DNS I selected 'Use the following Static DNS IP address' and entered the IP address of the PiHole as the primary and 8.8.8.8 as the secondary. After hitting 'Apply', the 'Status/Summary' screen under 'WAN' shows these two addresses as Primary and Secondary DNS Server entries.
However, Status/WAN page shows the DNS addresses as those of my IP provider and the System Log says these latter two addresses are being used.
I know the PiHole isn't currently being used for DNS queries as my webpages are festooned with adverts. BTW, it worked perfectly well with my 7800N.
I also appear to have found a bug when reassigning the LAN IP address of the router to 192.168.x.1, the DHCP range includes x.1 and does assign it (as I found out!)
Any remedies gratefully received!

[nightcustard]

I appear to have stumbled on a solution by changing the name of the LAN network under 'DNS Proxy' from 'home.network' to 'test'. I've left the broadband router name as 'home.gateway'. I'll have to do some research to understand why this works. The IP provider's DNS addresses are still listed on the 'WAN info' page but the PiHole PC now appears to be providing the DNS data (as evidenced by the lack of adverts).

[underzone]

In your router settings you should specify only the pi-hole server for DNS, the secondary 8.8.8.8 should not be there.
Then in the pi-hole config you can specify the upstream servers which will be used (you can specify 8.8.8.8 and 8.8.4.4 there if you wish).

[nightcustard]

Thanks for the reply - I'd read someone's view that you should have the router's secondary DNS address set in case the PiHole server became unavailable - from this I assumed that use of the secondary DNS address was a rare event, caused by some unusual outage. The penny dropped when I saw the PiHole traffic logs and realised both primary and secondary are used frequently (I think the ratio was about 60:40 for the period I viewed).
Ah well! Another learning experience
Cheers, Mike