Please PM me with your account number and area reference and I can take a look at this for you.
I am a Virgin Field Technician. All and any advice given is based on my experience in the field or my personal experiences with my own set up at home. If my answer was helpful to you please mark as helpful or consider leaving the post some kudos.
My guess is that Virgins network is not designed for this kind of aggregated traffic (everybody trying to video-conference from home) and we simply are hitting the limit of the overall traffic in these areas.
Whatever your package is / what speed you should have is irrelevant.
And, for support to keep telling us to check wifi settings and resetting our modems is also completely pointless (but distracting us from there real issue).