I'm not sure, if it's considered a "bug" anymore... It's an exploit, but the game recongnizes it, if you use it. (Just continue after using the exploit, and you'll see.)
So, it seems, either that it is not fixed on pupose, or it's just not possible to fix this "bug".
Either way, it's a good way to add the one or other extra point. You don't need ot spend *all* points, if you want to use the exploit. (for example, I like to select the background for the tremere, that enables to select the social subcatgorie. I just add one point and change again. The *available* points from the former background are NOT saved, only the spent ones.)
However: you need ot spend *all* points from the last page you visit.
The points are not activated, as long as you don't switch to the according screen. So, you certainly can read about all the backgrounds available. Select the one, that interests you, and if you don't like it, got back without spending any point.
However, I'm not sure, what happens, if you spend some points, and then select another clan. At least, I don't recommend that, espeically, when you have spent points into the deisciplines.