Did you check the the workout settings on the watch itself? You can choose to show the data screen and what appears on it. You can only do this from the watch. If you have the workout tile active, go to that and tap the "more" circle. Center the exercise in question and tap on settings. Scroll down to "workout screen" and tap it. Select data screen 1 and turn it on. Tap it to select the layout and tap each layout option to see which stats will show in that layout. If you are not using the workout tile, you can get to this setting by opening the health app on the watch, selecting workout and then follow the steps as above. 
