iCloud for Windows not fully initialized.

The very same kind of troubleshooting and conclusion was made with me when I've contacted Apple. So I confirm that, if you create a brand new user profile in your Windows 10 or 11, than iCloud 14.x will not give you any issue and so you'll be prompted - as expected - to satisfy the MFA multi factor authentication and than Login successfully - This aspect led me to the conclusion that the issue we are all facing and reporting here on this thread is most probably caused by something going wrong during the "iCloud local app profile migration from the legacy version 7.x to the new current iCloud local Ms App 14.x". I am 100% sure about this root cause because, as WPeterG and myself experienced, when you create a new Windows profile and you install from zero iCloud by the Ms Store, than you will succeed to authenticate and use it fully. On the contrary, in my opinion, if you were using (in W10 or W11) iCloud 7.x happily and than migrate to iCloud 14.x than you'll most probably face this kind of challenge. I hope these notes will help you all users and also Apple Support to investigate deeper, reproduce the issue on their side as well and finally get it solved in collaboration with Ms Store hub. Thank you!