Hello, MacroDroidDev.
As I said, this is all my fault! I created this confusion when actually everything is normal.
As you know, when one taps the Enable/Disable Macro action, in order to add it to the current macro, immediately a dialog appears where the macro to be enabled or disabled must be chosen. At the top, appear the special options "[Enter macro name]" and "[This macro]" and then all the other options are just an alphabetical list of all the macros in the device. It just happens that, while experimenting, I tapped that action icon, the dialog appeared as normal but, since I had forgotten all about two macros I had downloaded some time before from the Templates section, named "Trigger on clear apps from recents" and "New triggers", respectively, when those two macro names came up in the list I didn't recognize them and thought they were also special options (which was stupid, since they were not at the top and were not surrounded by square brackets). Only later did I realize my idiocy!
Sorry for wasting your time and keep up the good work.