Is the gluten in hard red wheat winter flour responsible for pasta stickiness during cooking?
Flour ground from winter wheat produces a much stronger and heavier dough for pasta. It contains a higher level of gluten than unbleached white or wheat flour which gives the pasta more elasticity and makes it easier to shape and put through a pasta machine. The problem is flour with high gluten content is often very sticky and makes it easier for the pasta to stick together and clump while boiling.
If you like this winter wheat flour though, you can mix it with unbleached white flour to give you a stronger dough that won't clump while boiling.
Here's a useful link on different types of flour for homemade pasta.