Nigel, Esq.,

Thank you for responding to my query.

As given previously,

Private Sub Worksheet_Calculate(), in this particular instance, is
deployed in waiting for "ActiveSheet.AutoFilter" actuation alone.

The question is, to devise a certain means,
to isolate, Private Sub Worksheet_Calculate(), such that it would not
respond to extraneous activation by, Autofit, UnDo, ReDo and probably
a multiplicity of other (spurious) button-clicking.

Private Sub Worksheet_Calculate(),
is meant for "ActiveSheet.AutoFilter",
out of exclusive necessity in this application.

Please share your experience. Regards.