More than one MIDI key editor.

I was editing in more than one MIDI key editor window but all of a sudden, some option perhaps that I deactivated by accident, by double clicking on the VSTi track the previously open MIDI Key editor is substitued by the new one.

How can I get back the functionality of having many MIDI Key Editors simultaneously?

That would be “Link Editors” in Preferences>Editing– deactivate it.

Thanks that worked.