@Marko Kikelj,Thanks for posting in Q&A.
Since you have no rights on the computer and can't even set new user with privileges, you can try to change to local admin account and create a new user.
Or we can try to unenroll the device, delete the device record in Microsoft Entra. Then enroll it again via Settings app > Accounts to Join this device to Azure Active Directory.
If above information cannot solve the issue, it is suggested that we set up windows from scratch.
Hope it will help.
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