These tests aren't exact/precise measurement like some piece of lab equipment. My DYS DD had a 1 point drop between the end of 4th and the end of 5th grade. She also had a 19 point jump between Winter and Spring of 4th grade. She was then up 8 by the start of 6th (over summer break) then a drop of 4 by the winter. Etc. Short story - you need more than one year of data and to look at longer-term trends and many inputs. I certainly wouldn't translate two data points from one test as an entire year of no growth.
You can use it as a data point in a broader discussion about learning plans, but it's not a waving red flag, IMHO.
