I'll tell you about my dd and hope that it helps.
We were called in for her not listening in reception and sometimes not complying. She spent a lot of the free play time in imaginative roles - so much so that the teacher feared she wasn't aware of reality.
I knew she knew what was real and what wasn't so I didn't worry. I did worry about her lack of concentration though.
She didn't really do well with the teaching from a white board where the whole class sat on a carpet. By that I mean she would often be rolling around with her back to the teacher. But the funny thing was, she was learning. She just found the pace a bit slow. She went on to be an outstanding reader by the end of year 1 and in top group for maths.
She still doesn't look like she's listening (age 7) and sometimes she isn't - often maths instructions have to be explained to her twice - the teacher does it on the whiteboard then the classroom assistant just asks her if she knows what she's meant to be doing.
I asked at the end of year 1 if she was the only one like this and should I be seeking help. The teacher said no, there's at least five others like this.
I think by mentioning it to you they just want you to focus on developing concentration - maybe by playing ever longer board games or doing harder and harder puzzles.
She is definitely not alone in not concentrating in reception. It's not really bad behaviour, other people have much bigger problems - believe me. For whatever reason she finds it hard to concentrate. That might be because she's shy and anxious, is getting used to a new environment, or just her mind moves a bit quicker or slower than the pace that's being used.
Mine at 7 is just about realising the importance of trying. Her work can be really sloppy but she's beginning to understand.
I just remind mine - you must listen and try your best, but I don't really go further in explaining than that.
At the end of the day - your's is reading really well. Focus on that. The great thing about it is that mine has a great imagination for stories - she has no problems with ideas for creative writing.
I have to ask her at least four times to put her shoes on though.