Captivate alt text on different button states not working with JAWS

I have a custom play / pause button for my course that uses an advanced action and states. I'm running into a problem during 508 compliance review where I need to have unique alternative text for both the play state and the pause state of the same button (so a learner hears the appropriate text read when tabbing to the button based on whether the course is currently paused or playing). I tried using state view and editing the alt text in each unique state. However, when testing with JAWS, the screenreader does not pick up any of the alt text designated in the different states. JAWS only reads the alt text (or lack thereof) for the default normal state. Has anyone run into this before and know of any workarounds? Thanks!