The fact that you're getting lots of viewings shows that people are curious enough to have a look, and the demand is there, but there is something or several things about your house which is putting people off from making offers. Rather than haggle you down to 230k for example, they just think it's easier to wait for another house or have found a better one elsewhere.
Many, MANY sellers put their house on the market in 2022, hoping to catch that COVID buzz, but things have really calmed down since then. I've seen houses in my area decrease by 30k. One house went from around 250k or more to 140k!
Rather than accept, that many people have just hung on and on and on, instead of reducing the price adequately.
The floor plan suggests that rather than this being a comfortable 5 bedroom house, it's an house with 5 uncomfortable sized bedrooms.
Bedroom 1 should have been one longer, more comfortable room rather than the fad for putting in on-suites in these days. He may have bought the house like that and had no choice though.
I mean my God, you have a toilet downstairs if you really needed an extra one for emergencies!
Bedroom 2 (at the front)- another en-suite! Silly! Imagine how big that would be if that wasn't there? It could be a really decent wardrobe space then.
Bedroom 5 - this is not a bedroom. It's a cupboard space. I'm not even sure if by modern housing standards that would actually pass for a bedroom space for an adult (I think it has to be a minium of 6 square meters). Still, estate agents will list them as 'bedrooms' all the same. Bedroom 5 & 2 are obviously meant to be the same room. Just looks like someone put in a partition.
Bedroom 2 (at the back, which should be labelled as '3' - looks ok.
Bedroom 4 - would make a smallish ok bedroom or study.
Downstairs looks fine - great big conservatory. That needs to be totally decluttered and new photos taken as it's the selling point of the interior, in my view.
You said smell - I wouldn't count on your house not smelling. Many families with kids would say the same, but people get used to their own smell after a while.
I'd put on a bit of eucalyptus globulus on a burner in there for an hour or so on each level of the house. I used to uy Neal's Yard one which is more expensive, but good. It's very good at neutralising any body type smells, and will give the air a faint green, minty tint to it. Don't over-do it though. 6-7 drops will be fine, and you might want to have look if it'll affect any pets or kids first.