You clearly did not bother reading my post at all.
- I do not "keep insisting" it was my first post.
- I am far from certain the whole issue is Private Relay (but it certainly does have something (rather than nothing) to do with it)
I quote from configure DNS for my wifi network
"DNS requests are being routed by iCloud Private Relay for this Wi-Fi network. Turn off Private Relay to manually configure DNS settings".
Further following instructions on how to turn off Private Relay in settings Apple ID>iCloud I find Private Relay(Beta). There have an option to "Upgrade" which produces a pop up to do so. There is no option to turn Private Relay off.
IOS either does use Private Relay without the means for users not using iCloud+ to disable it or there is some other issue with IOS networking that IOS itself reports incorrectly.
IMO, after the changes I made at router level, I do believe dns at least is handled correctly for domains not already visited (on the Private Relay dns or whatever we are talking about here). It is clear however that those that were visited have a persistent cache somewhere that resists dns flushing from the phone and router and deletion of the Safari cache.
Other devices on the network resolve dns correctly. The Dig app on my IOS device resolves dns from the local DNS resolver but Safari does not. Something appears to be hard coded that treats traffic (and I admit I have only observer dns in my limited test) in a different way with no option for the user to disable it.
I think that is enough detail if you do have something useful to contribute. I'd be quite happy if you are right and can explain the behaviour or how to control it.