Red button registered disabled

Hello, I am working on a PowerPoint intended for elementary students. Generally, the save function shows me a red button to record from my microphone. On one presentation, the red button is grayed out, and I need to go into Camtasia to activate it. I record my comment, and I can play it back by clicking on the sound icon of the slide, but it refuses to play during slide show mode. Its animation pane is set to "after previous" or on click, but nothing works. If I copy this audio to another PowerPoint, it plays correctly...

Thank you in advance