VS2019 Version 16.6.2, Windows 10 Dell XPS 15 laptop

For some reason I'm getting infinite loop problems when uploading via USB to an Arduino Mega 2560.  I get continuous scrolling in the output window, and the only way to recover is to open Task Manager and kill the VS 2019 app.  Needless to say, this is a bit frustrating.

It's hard to tell what's going on, as the text scrolls too fast to read.  However, I did manage to capture a bit of it using a cellphone camera (see attached). Basically avrdude is reporting an infinite number of read/write errors and never seems to time out.

Any ideas what is going on here?

TIA,

Frank

I have attached a txt file containing the verbose build output with build properties enabled, and the upload output after killing avrdude. 

However, I think this may be more of a hardware problem.   I cannot replicate the problem with a known-good Mega 2560, but can replicate it reliably with the suspect Mega 2560 from my robot project.

Frank