text: Sorry my full time job is insane this time of year. I restored a backup, and still do not have the handlers that I had originally coded. I had compiled a standalone app before Big Sur, and when I run that app the data grid does everything that I had implemented. Very strange! With some time off now I'll dig into this further and let you all know what I find.
  So what I have found is that I am missing the "Edit Script" (and "Inspect Object") button from the Object Inspector window. Is there a way to get to the code via another way? I'd post a screen shot but I can't seem to post images here.