There's no internal access between the main house and annex. So any buyer who didn't want a separate granny/staff flat, just a one- family home, would face immediate building works.
Floor plan, prepared by estate agent, full of sloppy errors.
On the ground floor plan, the bathroom has no door access at all.
Upstairs, the shower room labelled "en suite" isn't en suite to either bedroom. . Its only access is communal, from the landing.
In the annex, the bathroom has a double door to the kitchen (against building regulations)
That's a black mark against the estate agent who prepared the floorplan, and may reflect an equally slapdash, casual, amateurish shoddy and careless approach to marketing it.
L shaped kitchen diner; the room sizes are disproportionate. Again, potential building work.
Because of that, the price might be too high.
Rightmove says
"Properties in Merefield had an overall average price of £445,000 over the last year.Overall, sold prices in Merefield over the last year were 13% down on the previous year and 1% up on the 2019 peak of £440,000."