Okay I got another stupid question. You have everything going to the rear of the pc, but often times motherboards will have a riser to send audio to the front or top of the case so you can plug your headset in there. Do you have this facility and if so does running to it make any difference?
I may end up having to bow out but if I donāt get to keep trying to help: at some point youāll need to fire up a daw or obs or jack or something to figure out if you can actually see the signal youāre dealing with anywhere.
The troubleshooting process Iām working through is more akin to what youād do if you were at a big old mixing console trying to figure out why thereās no sound as opposed to the seemingly more obvious process of tracing device drivers and whatnot.
Itās been very helpful to me when troubleshooting sound issues āin the boxā, so if you get stumped fiddlefarting around with lspci and whatnot, give it a shot from that side.
If you can accept 11ā the old intel macbook airs are what youāre asking for.
Theyāre in the free - $50 price range now.