I often am working with two Arduino modules at the same time and have two (or more) VS2019 instances active, each one communicating with its Arduino module on a different COM port.  I have noticed that when I upload a program to one module using its COM port, the COM port of the other instance gets changed to the same port number.

For instance, right now I'm working with a Teensy 3.5 module on COM port 4, and an Arduino Mega on COM port 8.  When I click on F5 in the Teensy program to upload the program via COM 4, the Arduino Mega  VS2019 instance COM port changes from 8 to 4 at the conclusion of the upload.  If I then change the port number back to 8 to program the Mega, the Teensy VS2019 instance port number gets changed to 8 right after the program uploads.

I don't know if this is a VS2019 issue or a VM issue.  Has anyone else seen this?

TIA,

Frank