If Windows continually tries to install updates when you shut down and then configure them for several minutes when you power your system on, the update is more than likely stuck.
What to Do When Your Windows Update is Stuck | WhatsaByte Apr 27, 2020 Windows update gets stuck at 91% - Microsoft Community Jul 19, 2017
In Windows 10 you can find the Windows Update page by launching the Settings app from the Start menu and clicking Update & Security – if there's something wrong and Windows knows what it is then
Different Solutions for Windows 10 update Stuck at 90% Jun 10, 2019 Windows 10 Upgrade Assistant is stuck at 99%
Aug 20, 2018
Different Solutions for Windows 10 update Stuck at 90% Jun 10, 2019