Update to my [NichiyoDaikusan] post above:
Found a workaround from https://discussions.apple.com/thread/252471137?answerId=254689658022#254689658022
Copied from Eau Rouge' entry:
"There is a workaround.
Open Activity Monitor from your Applications> Utilities folder.
Click on CPU and in the Search field enter appstoreagent,
now highlight appstoreagent in the list, see below.
click on the info button, and press Quit> force Quit. [or click on the "View" drop down menu then "quit process" ⌥⌘Q] "

The following entry after Eau Rouges post by implied64 has the answer!!!
THE App Store MUST BE OPENED when force quitting the appstoreagent. And yes you have to kill it twice before it goes away.
Was able to complete all the updates without killing appstoreagent again after the first update.