I only have a few quick minutes to reply, and I'm not a professional
aeh has given you excellent and thorough advice above, I have just a few things to add.
My ds (now in high school) has fine motor dysgraphia. He can spell extremely well when he's not writing a sentence or working on a written composition, but his spelling while composing written work is extremely poor. If you google dysgraphia, you'll find there are different types with different symptoms, including differences in whether or not spelling ability is impacted. To briefly explain why some dysgraphics can spell really well when they *aren't* using handwriting: dysgraphia impacts the development of automaticity of handwriting - neurotypical children develop automatic handwriting so that as they move forward from learning how to write letters their brain isn't thinking about how to write the letter each time their pencil touches paper, and they are instead able to use their working memory to spell correctly, use punctuation and grammar correctly etc, as well as focus on the ideas they are attempting to communicate and how to organize those ideas. Dysgraphic students are having to redraw or rethink how to draw each letter each time they write, hence they have no working memory available to focus on spelling etc.
When I saw your ds' achievement scores listed above, they reminded me of my ds' first set of WJ achievement scores, and your description of him reminds me a lot of my ds at the same age, prior to his dysgraphia diagnosis. I'll try to come back later when I have a bit more time and tell you about some of the things we did at home that illustrated dysgraphia was an issue. We were doing those things after diagnosis (because his diagnosis was quite a surprise to us, even though the signs were clearly there, we just didn't know anything about it at the time)... but they might be helpful for you in determining if you think there's possibly an issue with dysgraphia.
Best wishes,
polarbear
