If your vegan pumpkin cinnamon rolls don't rise, the problem lies with the yeast. Either the yeast is old and didn't activate, or the location used to prove the dough is too cool. Look for a warmer spot or turn the oven on low and set the pan on the stovetop. Also, make sure the salt doesn't touch the yeast when mixing up the dough and don't add very hot liquids to the dough.