I’m definitely not a printing expert but it looks like you’re under extruding, is the extruder the same size as the old one or is there some other change like that? I say this because the bottom layers look better than the higher ones, from memory cura over extrudes for the first few layers to help with bed adhesion.

For sewing stretchy fabrics my advice is to purchase an overlocker not a sewing machine, sewing machines will generally suck at stitching stretchy fabrics. If all you have is a sewing machine I recommend triple stitching if your machine has that as a setting.

I’m not a professional at this, I just repair my family’s clothes so if I’m wrong feel free to correct me.