SDXL does this by default but tends to muddy up the shapes into blocks and hyperventilate on the pieces (depending on model) more often than not. This doesn't turn things into jigsaw puzzles, but rather makes things from jigsaw puzzle pieces, to whatever extent SD understands jigsaw puzzle pieces. I'm still not the best at these but I recommend mixtapexl_vol2

https://civarchive.com/models/223351?modelVersionId=261851

Str 0.7-1.0

<x> made from jigsaw pieces

also multicolored jigsaw pieces

standing will help objects stand up