Samsung Galaxy Tab Facebook Social Login not Working

I have a Balance 580 7.0.1 with a Captive Portal and Facebook Login enabled across my non-peplink Wifi network.
It works mostly fine with OSX Laptop, iOS iPhone and iPad and Google Pixel. Sometimes these devices report SSL certificate errors.

But we have a:
Galaxy Tab SM-T355Y
Android Version 6.0.1
All software up to date

It will display the Captive Portal, but you accept the Term and Conditions, select Facebook and the page reloads the Captive Portal again.

Anyone seen this before?

cheers,

Paul

Please open ticket. We need to check and understand your setup.

Thanks.