Together with Chat GPT we found that Windows Update was functioning correctly, but Feature Updates were not offered because the system was stuck in an experimental/continuous-innovation configuration, causing the OS to treat Feature Updates as “Not Applicable”.
A PowerShell script was created and executed (as Administrator) to:
Disable Continuous Innovation
Remove experimental TargetingAttributes
Clean WindowsSelfHost / OneSettings remnants
Confirm MoSetup AllowUpgrade
Restart Windows Update services
Force a fresh Appraiser compatibility run
After running the script and rebooting, Windows Update should re-evaluate Feature Update eligibility.
These actions didn't help, but most likely create a basis for next step:
I've downloaded and run file windows11.0-kb5027397-x64.msu (available at https://catalog.sf.dl.delivery.mp.microsoft.com/filestreamingservice/files/caa3ff4a-6420-4341-aeae-33b2d7f463be/public/windows11.0-kb5027397-x64_3a9c368e239bb928c32a790cf1663338d2cad472.msu)
after it's installation and reboot OS version changed to 23H2 and windows update started downloading Cumulative update