The variables panel does not seem to get redrawn as often as it should.

I am using the latest (early 2019) version of AI.

Create a new document.

Go to/open Variables panel

Panel corner menu->Create Variable.

Dialog opens: Enter name and choose type.

Close dialog.

New variable does not appear in list. (Yet)

Close and reopen Variables panel (or switch panel tab away and back)

Variable previously created is now visible.

Similarly, binding variables to objects is not updated in the panel without the close/reopen or tab switch trick forcing the panel to redraw.