I think you are probably talking about the icons in the Google Chrome address bar which indicate the security status of the website to which you are connected. I captured image 1 below early this evening. The “i in a circle” indicates that this link is running over what Chrome considers to be an insecure connection.
I captured image 2 later this evening via a different tab in the same Chrome browser. The padlock indicates a secure connection.
I can only suggest that some part of the website was configured incorrectly earlier in the day, but had been corrected by late evening.
If you click on the exclamation mark - it'll tell you!
The most common cause of this is indeed https: connections where the images are actually on http resources instead. We see here that the certificate is valid (except it's not - but that's a different story), and if we wanted to double check this we can actually click the certificate entry too.
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.