It turned out that there was an orphaned (left over from earlier development activities) process that was "processing" files from the same directory. This orphaned process had the same name as the desired process; but either the orphaned or the desired process had some kind of suffix to differentiate the two.
Having unpublished (and subsequently deleted) the earlier object should have removed it from the environment. Yet it was not deleted. How this came about, and how to removed the undesirable object become a different issue.