After Delightful Reading 3

So my son (8.5, 3rd grade) finished up delightful reading 3 at the end of this past school year.  I had him practice reading over the summer with the pathways readers and was planning on having him continue to practice reading aloud with the pathways readers this school year, and use the Copybook reader alongside, thinking he would just take off with reading, like my oldest daughter.  However I think he needs some more instruction? He is currently reading, and almost done with, More Days Go By and doing pretty well with that (as long as he gives it his full attention) but outside this book he greatly struggles. He is not super interested in reading for himself.  I have a daughter who is dyslexic and I do not see any of the markers with him, my gut is telling me he is just on the later end of the learning to read spectrum, I’m not worried, I just want to diligently work with him a bit everyday… and I’m not sure where to head next. Would Hymns in Prose be a logical next step?