Windows 11 not working power saving mode?

[Dmitry_TSLA]

I watched the movie, the phone rang and walked away from the laptop, out of the corner of my eye I noticed how the screen darkened a little (well, as it was at 10, this is a special darkening of the screen, after the screen is completely turned off, the power saving mode is shorter)
After I noticed how the screen returned to its previous brightness, although no one touched it, it means that inactivity continued and he should not have improved the brightness, after talking he returned to the laptop and started the film, but it did not start, pressed esc to exit full-screen mode, 0 reactions
Windows button also 0 reactions, task manager, execute command, nothing started the whole system hung
After waiting 5-10 minutes, I realized that this was a waste of time and had to turn off the laptop with a hard shutdown
The system is fully compatible with no edits and is fully compatible with the check program.
So there is a possibility that the power saving mode is also faulty.
I am using Windows 11 with all the latest updates, I am a member of the program insider. I understand that this is a dev release, I just report a possible error.

[#2]

@Dmitry_TSLA 

exact the same problem here...hope there will be a fix in near future.

[#3]

System cooling policy is gone and most probably the part that tells the CPU to throttle down to stock as well.

Re: BUG: Windows 11 Power saver plan - Microsoft Tech Community

[#4]

I have/had this problem and have read the many pages Google presents for 'fixing' the issue.
Once you have been through the basic, sometimes patronising suggestions, there seems to be no more help.
I began stopping services one at a time until the power saving mode started working again (set your screen blanking to one minute or you will grow old trying this!!!).
For me, it was the Logitech Solar Keyboard Service for my solar keyboard, but your's may be another service. I suggest trying anything that utilises a USB device. Once I stopped the service the screen went blank in the allotted minute.
This app is no longer supported and the Windows App Troubleshooter did report it as incompatible, but the 'fix' applied did not solve my problem.
As this was working before and now isn't, I guess that something has been updated in one of the Windows Updates which is causing this to fail the power saving utility.
At least I now know what the issue is and have uninstalled the Keyboard Solar Service app and my investigations continue...