Image Alt text fails to display on mouse hover

[TechWriter2020]

I've tagged a PDF. I've added alternernate text to figures. However, the figures alt text is failing to display when I hover over the figure.

How do I fix this? I've added alt text to the "Set Alternate Text" in the figures.

[scooterbyrd2003]

I have this same problem.

[sapryan]

I also have this problem. I've been told there is no way to control the hover feature.

I have a question in with Customer Support, but I'm not getting very far with them.