I know this is an old topic but I am having the same problem and do not know how to fix it.
I am using the latest version of the composer (6.0.4+157) and player.
I create a standard web browser asset and load the URL into it. This works perfectly when I test it in my windows player but refuses to load/run when I play it on my Android Tablet (Samsung).
I do have Chrome loaded as my default browser on both platforms.
The Matterport scene does work perfectly when I load it manually into the chrome browser on the tablet.
Any help would be greatly appreciated.
PS. I have also tested the demo scene that Tosolini created. Works fine on my windows laptop but does not load the Matterport scene on the Android tablet.