Thanks for responding.
No mistake on my part... triple checked it. I logged a support ticket which has been escalated but not resolved. At this point my listing setup correctly shows a 10 day minimum as it always has, but my trial bookings allow any length of booking and have "1 day minimum" above the date picker calendar.
I also asked the support tech to do something about the "1 booking - 1 cancellation" demerit since this issue is obviously related to a system glitch.
Will definitely keep instant booking off at least until this issue is resolved, if not forever.
Thanks again. jr