@eoverton70,
In addition to what @chriscas wrote, there is a weird workflow that repeatedly catches people until they become aware of it.
If you set the option to "use rubric for grading" before you find and attach a rubric, it does not remember (save) your settings.
What you need to do is attach the rubric. Then click the button to edit the rubric. Then check the box to use the rubric for grading and save the settings.
Unintuitive, which is so un-Canvas-like, but hopefully it helps you understand. If you're like I was until I figured it out, you were probably saying "I know I checked the box but now it's not working." To Canvas, the checking of the box never got saved because you "changed your mind about the settings" and decided to change the rubric instead. Technically speaking, the new rubric might have different settings, but most people were probably changing the settings based on the rubric they intended to use, not the one that was there.