It's boiled down to this, Openreach say that we have Fibre to the premises, which is not true
If the wholesale checker says WBC FTTP is available, which means Sky are also happy to take your order, then you should simply order it.
In my experience, if the Openreach database says it's available to order, they will jump through hoops to complete the installation: i.e. it's rare that they will cancel the order because it's undeliverable, although that does sometimes happen.
Example in point: I had FTTPoD installed in 2019. As part of that installation, they marked three other properties in my road as having FTTP available. But two of them were not my immediate neighbours, and one didn't even have any ducting from the footway box outside my house.
Both have placed orders - one via Vodafone and one via Plusnet, who said at contract renewal time that they should upgrade to FTTP, because database says it was available.
In the end, Openreach completed the installations, actually digging up the footway to install new ducting to one of the properties. It took several months, but they *did* get their FTTP service in the end, for free (which I don't mind at all: very happy for others to get some benefit from my FTTPoD).
The rest of the street still don't have FTTP, and our exchange area was only added into the FTTP rollout plans in the last batch announced a few weeks ago.
Anyway: just order FTTP and be done with it. Given that it could take several months, your options for service in the mean time would be:
1. Take FTTC from a provider who offers short contracts, like Aquiss. (You can take a 1-month contract, although because of the setup fee if you end up taking it for more than 6 months it would be cheaper to take 12). Make this a completely separate order from your FTTP.
Aquiss are also clueful and will be able to order FTTC even at a property where FTTP is available (as long as you're not in a stop sell area). Other clueful providers are available.
2. Use a 4G/5G router if you have decent enough coverage
3. Starlink.