I found the solution, rather in an unexpected area. The visibility of the drop-down menu is found to be connected with the
setting of the Providence. In my case, in the
settings for the
, when I changed the
for
category from
to
, the drop-down menu came back in the
page.
I have attached here a screen shot to explain what I mean.
Thank you darrigan, for patiently responding to all my queries.