Cannot remove product variations

In the settings for each individual product, there is the option to put in "variations," for something like size, color, etc. In several instances, I have added variations and then needed to remove one. However, it ONLY allows me to remove the last/most recent one added. I need to be able to remove any of them I choose. Is it only possible to remove the last variation entered? See attached screenshot. The last item, "navy," has a red X by it. I can click that red X and delete that variation, but I can't delete any others. Is this something we can fix?