DD in Year 1, very similar, able, bright etc. etc. etc. All the usual things, including very articulate, good vocab. Slow with reading and had extra help, but no problems came out and finished the scheme before others on the same one.
Just a very disinterested child in school, happy to go, but not motivated (yes at 6!). I was beginning to think there were learning problems, teachers said was too early. Despite being oldest in class she was just muddling along, struggling with maths. Distracted, produced very little work, unless sat next to a TA, when she would do good written work.
Year 2, we moved her to another school, an independent, explained our concerns. Within weeks she was motivated, interested in her work, happy and working hard to improve her writing, all with no major input or nagging from us.
Start of Year 3, she was/is above average in literacy, usually gets 15/15 in spellings and dictation and 30/30 in tables tests. Her maths is very slightly below average in the class, but they have just had another assessment and it will be interesting to see if there is a continued improvement, but in all other areas, working hard and achieving.
There are obviously no major learning difficulties, she can be a bit forgetful, often leaves reading book at school etc., but they are working on her independence (only child and I think I do too much!).
Personally, I think the teacher and school just didn't motivate her. In her new school, motivating and doing your best is a given by everyone, it is so dynamic in the whole ethos and it shows.