Slide audio continues after NEXT selected
I am using Captivate 2019 Release: 11.5.5.553
I have a 12-second audio stinger (music) on a title slide. The slide has one button set to "Go To Next Slide" on click and a pause at the 11-second mark. (Animations occur before the pause to introduce the course). The button is a png image that I have activated as a button.
In setting it up, I select the button and navigate to Properties > Options. There I select the "Stop Slide Audio" option along with the "When Clicked" option .
When I preview with HTML and/or publish the course, and it begins to play the animations and audio, Before it pauses, I select the NEXT button. I am taken to the next slide but the audio continues to play to full completion. I do NOT have this same problem on other slides within the course where slides have recorded audio. I also tried turning on the PLAYBACK CONTROL options to see if that would produce a different result but it does not.
I have let the audio play to completion and advanced the slide, then I use the back button to replay this Title slide with audio, and the audio DOES stop when advancing to the next slide. So just the very first time into the Title slide, the audio is always playing the full length regardless of hitting next, back, or pause.
I have tried taking the audio off the slide and adding it to a graphic but the results were the same. I don't know what else to try. Any suggestions?

