I think we shouldn't get so hung up on how many sublevels of progress they 'must' make each year - and if we didn't have interfering governments and PITA OFSTED, teachers could just get on with teaching and be allowed to explain to parents that hey, children don't learn in a steady progression. Some do, but many stall, then leap, then progress, then leap, then stall again for a bit
We are talking about very young children here - their brains are still developing and sometimes you just have to wait patiently for the next step in neural development to take place. Yes, we need assessment, and yes, children should progress, but it would probably be better and less stressful if we all took a much longer term view of it, and also looked much more broadly. Some years our DCs might take leaps in writing and maths, other years their fine motor skills might be developing very rapidly, or their ability to think, reason and converse. We have such a narrow academically-focused curriculum now that a lot of 'human' talents and their development are going unnoticed.
My DD2 was assessed as L3 in everything at the end of Yr2 - now at the end of Yr3 she is 3a in maths, 4b in writing and 4c in reading, so only one sublevel for maths this year. And that's fine, because I know she finds maths harder than her other subjects, but she has made progress.
And she loves school and learning, which is ultimately what it is all about.