Can you share some more details about your configuration?
- What browser version is running in the tablets?
- For Chrome, it should be the direct browser version
- For Fully Kiosk, it depends on the WebView (Settings → Other Settings → Device Info)
- Is SSL enabled on TinyCam?
- If so, is it a valid SSL certificate?
I would recommend taking a look at the Mixed Content community post as it includes some notes about common issues with modern browsers and media along with some fixes / workarounds.