Do you have the item in your inventory that gives you a +1 to dex? If you do, it will look like it removes one of your dex points when you apply it. Just click accept and go back to the character sheet, and it should display it the right way again.
Stand your back against mine, and we shall carry the weight of the world
I didnt have anything that added dex to my guy, but the armor that took -2 away. but when i clicked to add another dex point, it took one away and i had double XP points to add to stats.
I had the same exact problem. I used my stat points elsewhere, then after getting more I went back and kept clicking on the one I wanted until it would finally register.