There's a few things awry here.
This series looks like a boxset (it's not been broadcast in the past 30days), so the complete series should be available in any particular format - i.e. SD/HD/UHD - and for starters, that's all over the place. E1, E2 & E4 are missing outright, and other episodes are inconsistent in their format. Some have SD, some have HD, some have UHD. That's a problem, will need VM to rectify, and I can pass that on.
Your issue is that SD & HD episodes are included in your box-set subscription, but UHD OnDemand is a separate add-on that would only be included in Ultimate Oomph if you moved or re-contracted onto that bundle after May 5th 2021.
I'm a Very Insightful Person, I'm here to share knowledge, I don't work for Virgin Media. Learn more
Have I helped? Click Mark as Helpful Answer or use Kudos to say thanks