It may or may not matter but I keep my seam stitches smaller than the open stitches. Looks like you top stitches are tight enough so I would suspect your seam stitches are the same. On my machine seam stitches are on 4mm and the top may be 6 to 7mm.
Hopefully others will chime in.
make sure to do relief cuts on the curves and corners don't force it or hold it tighter , cause that will cause your stitches look different and not even.
I use a shorter stitch (6mm) when joining panels and longer (10mm) for topstitching. Also try reducing the side pressure from your hand at the foot when topstitching ….. hope that makes sense.
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