Hi all, I had exactly the same issue as everyone here after an auto upgrade for Windows 11. I had followed all the steps people had suggested such as running the troubleshoot on my PC, and updating my driver, with the same response, saying it was already upgraded etc.
I am far from a PC pro, but this may help those with a Lenova Yoga, such as I have. I clicked on the 'Lenova Vantage' button in my taskbar (a dark blue square with a white capital 'L') apparently this is some sort of support service that came with my PC as it is only a few months old. (To continue with this I have to pay approx $52/year). It went onto a 'Support Services' page, and I clicked on 'System Update'. It took a few minutes to run, but after it had finished - voila, I had sound again!!
Maybe see if your PC has some sort of support service that you can do a 'System update' on if the driver update or the trouble shoot options don't work?
Good luck with trying to resolve a very frustrating issue! :)