Twitch embedded video problem

Don’t need to worry about the video id. It’s nothing to do with this because if it was you won’t be able to load this on one of the tablets.

You said you are using a webview on android. You can set a client for the webview and also enable JavaScript, do you do this? It could be that for one of the devices the settings default to something that works and on the other device the settings are different.