Honestly, to me your house looks fine. There’s always going to be things that people don’t like on any listing – too grey/beige, too much colour, too many bedrooms versus bathrooms or not enough bedrooms for the number of bathrooms, too much grass or not enough grass etc etc.
Things I don’t like though are you say you have reduced the price from £400k but the listing actually says offers in the region of £375K and the body of the text still indicates that the range is 375 to 400. That’s not really a reduction is it? I hate this business of offers over, just say what you want for the house!
I don’t know Swindon or the area particularly but there are a number of houses for sale in the area with very similar prices and layouts so people have lots of choice and there’s nothing particularly special that makes your house stand out.
It’s also a terrible market at the moment, everyone is worried about cost of living and fuel price increases and mortgage rates have gone up substantially over the past year so people are very anxious about making huge financial commitments.