This is how I see the terms … I’m pretty sure this is close if not actual
Track = Configuration and main Routing container…
Part = a Container of MIDI Events
Event(s) = The actual MIDI message data
You probably have what are called “shared copies”. If you look at the top right of one of the parts that is moving when you are editing in another part, it will have an equal “=” sign in the top right. Goto MIDI->Function->Convert to real copy.