Piety and Vitality question

[Nekodar]

Well - I'm not that far to be able to verify that but I know that in the box where you select the points to be added to the specific attribute it counts the added / remaining ones between 0 and 20 so unless it will change once you get higher level or is class depending I expect no to be able to add more than 20 to any of the atributes, unless indeed the GUI is just incorrect.

The GUI is correct in the sense that at the level you saw 20 at you had gotten a total of 20 bonus points to distribute.
You probably don't remember now but when you first got bonus points, the max listed then was how many points you got.