Both Firefox and Chrome are marking the Video content as unsafe and therefore blocking it. To view the videos, you need to allow unsafe content from Tynker and reload the page.
Chrome:
To allow mixed content in Google Chrome:
Click the shield icon in the far right of the address bar.
In the pop-up window, click Load anyway or Load unsafe script (depending on your Chrome version).
Note: The steps to "load anyway" must be completed for each page where the icon or message appears.
Firefox:
Unblock mixed content. Unblocking insecure elements is not recommended, but can be done if necessary:
Click the lock icon in the address bar.
Click the arrow on the Control Center:
Click Disable protection for now.