The system might be getting confused with too many changes all at once. I suggest first add all of your new categories then save. THen go back into category setup and remove the categories you no longer want and save that.
That’s a good suggestion, and I should have mentioned that I did try it. I tried deleting only one default category (banking), but that change did not stay. Then I tried to add just one custom category (hulu), and that did not stay :(