a "new MakeMKV instance" not working consistently (for me)

[audioguy]

I must be dong something wrong. When I try to start up "a new MakeMKV instance" (on a Mac) it seems to try to connect to the drive that is already running with the first instance. It messes up the first instance and I have to close down the 2nd instance. It works sometimes so there must be an order in which to do thing to make it work all of the time.

HELP!

[Woodstock]

Preferences->IO, "Ask for single drive mode", check the box and click OK, restart MakeMKV.