When you are in the development stage of your shop, most of the times there is a need to clear the store and browser cache to see the results of your changes, have you done that?
You need to set the new groups in your categories...
Also, have you checked all the boxes on the new group??
I just noticed that i have a recent demo store where i don´t have the default groups selection in "Groups" (it might be installed by a module), maybe you should´t change the default groups!
Best Regards