This is very similar to an issue that I and many other on this forum and indeed many people on social media are experiencing since Virgin implemented a disastrous recent firmware update to the Hub 4: https://community.virginmedia.com/t5/Speed/1Gig-Upload-speeds-dropped-from-52Mbps-to-10Mbps/td-p/526...
Virgin Media support are deliberately ignoring and not replying to any such low upload issue forum posts as they know there's a bigger issue here. Like you, I have checked the Virgin support status checker and the automated support phoneline and no local issues have been reported. Its shocking that Virgin leave customers with no support when things go wrong like this. I am trying to work from home and its making things very difficult between sending emails, using Teams and accessing websites in general.
I contacted the Virgin Media Broadband support phone line and they read from a script, told me they could find no fault, despite me alerting them that multiple speed tests on well established sites such as SpeedTest.net, SpeedTest custom and SamKnows Realspeed tests are all clearly showing an upload issue between the router and their infrastructure (0.0mb upload). They were completely useless and offered no resolution or additional help...where to go now?