Apple Watch not Counting Exercise

OK... My wife and I both have current model Apple Watches. We walk together every day. We walk a steady pace of 3 MPH for a total of 2.25 miles, which we complete in 45 minutes. Every day we get a different amount of time counted toward our exercise ring. We both use the workout app on the watch. Today, it counted a whopping 5 minutes for her and 35 minutes for me out of our 45 minute walk. Something's not right here! I've tried recalbrating, repairing, etc. HELP! This is terribly demotivating when you walk your tail off and don't get credit for it!