Tap to Unmute button issue w/ Firefox

Hello,

This plugin is great, but when the browser window is maximized in Firefox, the unmute button shows for just a second and disappears. It goes away too fast for the user to have an option to unmute the video. I am told this also happens in Opera and Safari. It seems to work fine in Chrome. Any fix for this?

Here is my client’s website:

https://leg-up.com/

Thanks!

The page I need help with: [log in to see the link]