I am having the same issue too.
Is there an update please?
yes the app won't sign in on any device and I have tried, Nivida Shield Tablet, Samsung Galaxy s7 and Motorola G3. Last week all were working fine.
It either claims the sign in details are wrong and tried captcha images, signs in and just shows the website or doesn't sign in at all with a "General Error"
I have cleared the app data (cache), removed the App & reinstalled and restarted the phone. It doesn't matter if I'm on home virgin wifi or 4g all the same.
Hopefully Virgin will fix this, but I won't hold my breath
a month ago