Thanks for checking the link Jordi. Much appreciated.
Just checked and it's Android 4.4.2. Looked on the Android website and see 5.0 is out although I've no idea when it's available for this tablet.
I looked under Chrome://flags and see that 'enable' is shown under Disable WebGL so that's active but when I go to
get.webgl.org it says that the browser supports WebGL but it's disabled or unavailable. This is on a SM-T700 (Samsung Galaxy Tab S 8.4) I got about 3 weeks ago so it's not old.
I just installed firefox on it and although the 360 shows correctly and there's no black tiles the sound won't play.
Very odd especially when it's normally iPad that's the pain.