Button Appearing Early in Preview Mode and Not in Accordance with Timeline

Hello! I have created a "Continue" button on multiple slides in my eLearning course I have developed to serve as navigation. I specifically edited the "Continue" button on the timeline to appear only after the audio is finished on each slide and layer. When editing my course and viewing objects in the timeline it appears as though I have done this correctly, but when I go to preview my course I have noticed the "Continue" button doesn't appear in accordance with the timing I have specified on my timeline. I am wondering if this is possibly an issue with layers, or if there is another setting I am missing.

I will include an example from the course I am creating for reference.

When in preview mode you will see the "Continue" button on the first layer doesn't appear until after the audio is finished, but on the second layer the button immediately appears after clicking the "Continue" button on layer 1 before the audio is finished, which is what I don't want. I haven't been using Storyline very long, so any help is appreciated! Thanks.