Thanks @Ellie it’s been baffling me.
Could be few reasons for this, as puzzles are created for different skills for example you can have a 9 piece puzzle that has a matching picture underneath, so they are matching the image not necessarily the shape. So a 4 piece with no images that you have to match via shape has a greater difficulty level. Both skills are great for supporting reading in the long term.
@Hayley Some are in a box sets. So 4 puzzles of varying numbers of pieces. He can do the 6/9/12 but finds the 4 difficult. I’m neurodivergent but not sure it’s related.
@Cal could be how the pieces go together on the 4
Not my boy, but my brain works like that. My teachers in school couldn't figure out why I could get all the complicated math questions right, but struggled with simple calculations. Could just be a simple overthinking and not believing it is actually as easy as it seems.