Low fat muffins won't rise
Muffin mix should be a pourable batter, not a thick dough, your mix is too dry. If it's too dry and claggy it won't be free to expand, and you don't get a rise from water vapor. Try adding more cashew milk until you get a pourable batter, and try it again. You want it to be ribbony, not so loose it evens out right away.