Thanks, broc. That does the trick. I would not have found that on my own. I did read thorough the entire metro reference, which has this to say about the active attribute:
"Turns the metro on and off"
Nor does it mention anywhere that autostart is not intended for use when the main transport is looping… If one is using Live for, say, "Live" instrumental recording/looping, is it that unusual to loop the main transport at a phrase length in session mode? I would have thought this was a common practice & this would have come up before. No other mention of this issue that I could find, and I looked…
Hope this thread saves someone else some frustration.
Thanks again for your quick response/help. I really appreciate it.