Here's the problem that caused me about 2 hours of t-shooting...
Object has two forms - could be that even with one form you could duplicate this. Form has multiple sections. On one section, I have two Separators. The first Separator had no Items in it and was followed immediately be a second Separator. In this condition, the form would not launch from a query. If I add an items under the first Separator, or delete the first Separator, all is well.
I had placed that Separator there planning to come back and add some content. Then this happened and my morning got tied up chasing it.