Still trying to find the underlying cause of this despite the replacement that I have had for the last month which is not behaving any different.
I thought I had managed to find a work around by getting the battery when plugged in to only charge to 50%. There is a setting in the BIOS (press the Power and Volume up button together to access) which allows you to enable this, but this has made no difference. :-( My theory being this might be related to fast charging, as the laptop behaves when it's not connected to either the supplied power adaptor or the Surface dock. Something has changed in the last 5-6 months as this was never an issue when I first received the device.
There have been some posts on setting the Power Management settings but have tried this and even some of the Power Shell commands but this has made no difference.
What I have noticed this evening is if I start the MS Edge browser (Chromium) this triggers the fan, but for some reason Chrome itself does not. Any other suggestions welcome, my IT team at work have told me they can replace my device with a Dell but I am reluctant to part with it.
Hoping for a fix soon!
OK it would appear my device seems to back to normal once again, even after all the Windows updates yesterday :-)
Hope this helps but I noticed Edge and a particular extension I was using (LastPass) was the actual offender (great tip from my internal IT team who suggested I start by disabling all extensions). Just to explain my usual flow of work involves having Outlook, Teams, Chrome (for my personal stuff) and Edge/Firefox open (for work related matters) as well as OneDrive and using other Office products (Word/Excel/Project/Visio etc).
I am not sure if the following PowerShell commands have also worked so worth a try and I am using the provided "Balanced" Power Plan with no changes (I did set-up a custom one but will leave the default one for now as it appears to work!):
powercfg -attributes SUB_PROCESSOR 94D3A615-A899-4AC5-AE2B-E4D8F634367F -ATTRIB_HIDE
powercfg -attributes SUB_PROCESSOR bc5038f7-23e0-4960-96da-33abaf5935ec -ATTRIB_HIDE
The only thing to add to the mix is that I downloaded the firmward updates a few days back from the MSFT site but my device was still misbehaving after these updates....
Good luck folks, just hope the device stays behaving...