I am sorry for the confusion this has been an odd issue and is quite difficult to explain as the issue kind of fixed itself but only by chance I will explain best I can below.
Just to be clear I am talking about the Asus Z690 HERO Board for this work around.
The way I got it to work does not make much sense but basically I plugged in one pair of headphones rear lime port and then another pair in the front port of my case.
Now since doing this the headphone impedance is auto detecting correctly and so is the speakers even though I would like it to see it as headphones.
So to rule this out I wanted to replicate this and see if this is a bug. I have now since tested with a clean install of windows 11 and the issue is back again ? But when I plug in two pairs headphones in rear and front port it is working again.
I have yet to figure out why on my original post I was having the wrong impedance being detected on just the rear port labelled speakers but something changed and that fixed itself. Maybe windows update did something who knows...
Pictures links below Front port and then Rear Port show working as they should apart from speakers label should say headphone rear or something along those lines.https://imgur.com/a/NOnbYc9https://imgur.com/a/U3rhcCn
I am unsure why the XI Gene was showing 420 I think it was intermittent and sometime over a 1000 but that system is showing the same similar problems to the Hero Z690 but with a couple more noticeable things.
I will put together a video showing all of this as I think the issue could be related and I think that is why there are some audio options that are currently missing from the z690 hero until a fix is made.
My windows version for the Z690 Hero and the Gene XI are the same just I have yet to fully update the windows drivers on the Gene XI because I want to test it before updates : Windows 11 Version 21H2 (Build 220000.434)