W10 Cumulative December Update KB4592438 - laptop behavior

Hi
Recently (i.e. December 2020), I installed the Windows Cumulative update KB4592438 on two Toshiba (dynabook) A-55 laptops running W10 Home 64-bit (build 19041.685) with i5-8250U processors.

Note, these are identical laptops bought at the same time and I administer both of them. Both laptops are scanned frequently with McAfee and HitmanPro.

The install went fine for one of the laptops (call it A) with no issues. When A restarted, I checked Settings>Windows Update and it confirmed the installation was successful.

On the other laptop (call it B), the install also was successful. However, upon restart I noticed there is a slight, yet noticeable difference in the restart cycle. First, the company logo and circularly spinning dots appear as before installation of KB4592438. The screen then goes black (no logo and no circularly spinning dots) and remains there for about 1 minute. Then the screen prompting for the PIN appears. I can log on and the laptop appears to work as before. It is this new 1 minute lag that has caught my attention. Note that A does not do this. It seems that B is waiting for something perhaps and then carries on when that “wait” times out.

I am interested in whether anyone else has experienced this. As the laptop appears to be working, I have not yet run DISM, SFC, or anything in TuneUp.Bat. I am just getting an idea for now as to whether this "new" behavior should be of concern.

Also note that a quick check of services.msc on both PCs reveals that Windows Update is in the manual (triggered) and running state. Windows Update Medic is in the manual state.

Thanks in advance for all feedback.