From the screen shot it looks like the chord symbol Cmi7 was not added with the Chord Tool, but rather with the Expression Tool.

The staff displays Slash Notation.

I would take a good look at the definition of the Slash Notation (= in the dialog box Alternate Notation).

Perhaps the Slash Notation is set up to, display Chords, but not Expressions.

I am using a midi keyboard to enter chords

I definitely select the chord tool (not expression)

for entering chords; sometimes typing in with QWERTY keyboard, sometimes using midi keyboard

Not sure why it’s happening, but right click in the handle of the greyed-out chords, and either check Show or uncheck Hide. (I don’t remember offhand which it is.)