Yes it may well do , and may explain the UG feed not evaluated survey note …..these type of sites can be unconventional, in that often the site owners build the infrastructure themselves to their own criteria , even if Openreach initially supplied the preformed joint boxes , frames and covers and ducts etc. so the infrastructure records OR have could be different to what was actually installed by the site owner , and if the dwelling is raised with a veranda around it , typically the case with these types of ‘static caravans’ or chalets and there is no evidence if the duct entering the dwelling because it’s hidden , and access to it may be tricky , it would be understandable that an OR engineer wouldn’t want to be working under a ‘building’ like this, looking for where the duct enters , it may even be the case the owner has to disassemble this structure to enable access , which may be a deal breaker if the owner cannot or will not do this.
However, if OR have said it has availability then it has availability and OR will be duty bound to try and provide it , a potential issue is if the site owner doesn’t allow OR access or places constraints or asks for payment , obviously that’s something outside of OR’s control, so there are reasons why installation can fail after the order has been accepted.
TBH , its often the case , when people post about the issues they are having , after a little probing it becomes clear that it’s a non standard provision to something of an out of the ordinary property, it really should surprise anyone in a property like this , that their order journey isn’t going to be as smooth as a standard property on a regular road/street , and in some respects, if the address isn’t liable for council tax , have a front door with a letter box ( so the Royal Mail have a postal address for it ) then it’s effectively a temporary address , then there is no universal service obligation on OR to serve these , obviously your address may be permanent and does fulfilling those criteria, but many network providers would simply not bother attempting to provide service to these type of locations as they are not worth the hassle.
There is a reasonable chance that Openreach have been to visit ( the first stage of the two stage process ) to assess ( evaluate ) what’s required, so the second stage can proceed once any first stage work has been completed , in a more conventional setting this first stage could require work in the public footpath ( which OR have the right to do as a utility with code powers so they don’t ask the council , they just serve notice as to when it’s getting done ) and obviously any work on the private property/land of the person ordering service hopefully would be agreed ( if no agreement can be reached , then it’s effectively a consumer cancellation )
…in your case it many be more complicated as although you own the property, the local authority don’t own the surroundings , hence the code powers to work in ‘public’ areas doesn’t apply , the site owner has to agree to any works.
As you have been advised of a delay , it’s hopefully because the site owner has yet to respond, rather than said ‘No you cannot do it’ ( regarding whatever was proposed ) , if the site has an ‘agent’ that you speak to about ‘ communal’ areas , you could ask if Openreach have been in touch .
Unfortunately the way the industry is set up ( an Ofcom imposition ) you have to speak to your provider and they speak to Openreach , where in cases like this it would be easier ( but it’s not allowed) if OR and yourself could ‘speak’ directly so you would be aware of what’s happening.
To have fixed wireless you would have to be in an area that one of these fixed wireless operators service, I don’t know if any checker site that shows availability, you may have reasonable 4/5G mobile coverage and could use this , or something like Starlink , a satellite based system ( AFAIK it’s not particularly cheap ) .