Heading 2 Text Style Not Applied Consistently

I have a course with several slides in which each slide has a slide title. I have diligently applied the Heading 2 style to each slide title. All are meant to be read by a JAWS screen reader.

But--very frustrating--the screen reader isn't announcing "Heading Level 2" before the alt text. 

I've tried:

• Reapplying the H2 style
• Creating a custom H2 style
• Copying/pasting a H2 slide title from another slide that is working
• Duplicating the entire slide and inserting into a new scene to reset it
• Opening a blank project file and importing my entire course into it

Nothing has worked. What does the staff recommend? One of the slides is attached.