Creating Pattern/ Pattern not connecting and overlapping

Hi there,

I was trying to create the photography of this floor tile as a tile pattern on illustrator.

So I created a row squares then copy and pasted it either side of the first row of squares to created the the pattern, as you can see by the images attached when I tried to create the repeat pattern the squares seemed to overlap and didn't connect. Could someone please tell me where I am going wrong? Is it the squares are not all the same size? I don't see how that could happen as I copy and pasted them all but before I went into the pattern maker I minimised the whole shape so maybe that effected the shape of some of the squares? Is there a way I can adjust this pattern without creating it all again or am I missing something?

Thank you so much!