I am experiencing the same issue. Prior to the update of Windows 11 on July 20th, my CPU was idling at 45C-50C on power saving mode at approx 2.2Ghz. After the switch over, with power saving mode on, its idling between 58C jumping to as much as 70+C (mostly around 64C) with a cpu usage of 2%-4% @ 1.7Ghz.
In the beginning I thought the power profile was the culprit as it is constantly bouncing between Ryzen balanced and Power saving mode on its own. I disabled reduced the processing power to max 45% turn boost off, and still no change.
Under loads the CPU temps would immediately jump to mid 80'sC and hit up to 95C.
When attempting to get answers from Microsoft, all I receive are generic responses such as, make sure there aren't too many apps running in the background, make sure there is proper airflow, no dust etc. These are not the case. I looked for the particular updates mentioned in this post, but I do not have them installed. virtualization is disabled, as well as indexing, and the problem persists. I hope that Microsoft takes this issue seriously and resolve it soon.
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Ryzen 9 3900x
MSI meg Ace x570
Saberent Rocket NVMe M.2
16GB DDR4 3600Mhz
360 aio cooler