Texture/map stretching on some UV's and not others.

I've had this problem a few times with various projects and just avoid using certain things in substance because I don't understand why it stretches like this on certain UV's even though the UV's themselves are all unfolded and set up. Here is a picture of what I mean by the stretching, I am using the black mask to show it off better of what I mean. https://imgur.com/3LaBrYv

Here is the UV in maya: https://imgur.com/ijwjQMw

Here is the UV in substance, the bigger UV islands work fine, but the smaller ones get that stretching: https://imgur.com/84nefGA