Why is my dough not very stretchy? I have tried simply dough recopies for potsticker wrappers or dough's slightly more involved like corn tortillas and no matter what, whenever I press the dough for shape it doesn't keep form and just shirnks back up.

I have tried rolling pins and tortillas presses, but as soon as it flattens within seconds it shrinks back up again.  I use a stand mixer to mix all the ingredients.  Does my issue maybe relate to not mixing long enough or maybe mixing too long?  any tips would be appreciated on how to make sure the dough keeps its shape after flattening.
you aren't letting it rest long enough....When I used to ruin (run, i meant run, but ruin is just too funny so I am leaving it there) a pizza restaurant, if you forgot to prep the dough the night before and allowed the dough to rest in the refer over night, the dough would be very stiff and springy....

In your case, without really knowing your recipes and so this is a stab in the dark, you probably just need to let the dough rest at room temp for 30 minutes.