We're having same issue, I thought there were problems in July when we were away and I couldn't always connect to security cameras at home.
Since start of August I've been keeping a record of when the router has dropped connection when I've been at home. It's been nearly everyday throughout August and that's based on me only been in early morning/evenings! It's as if the router is rebooting itself as it's usually only down for a couple of minutes.
Today it's just gone off again but this time it's rebooted twice within 5 minutes.
I'm going to try and get through to virgin media as it seems since they announced their raising prices again, broadband has started playing up!!!!