I have a tablet (Samsung 2 10.1). I have Avast premium mobile installed. There is one WEBSITE, not app, that if I open and even gently brush ANY part of the screen I'm met with "Android defender battery outdated blah blah blah" ad. I back page and I end up at the start up screen. This is driving me crazy as I now have to open website on the tablet and if I want to do anything on that site I have to get my laptop out. Any ideas ? Thanks