Jesh yours is not an issue it is how the option is designed.
If you add an extra field and want it to be created on all children it can only be done when you create it. Therefore you can not move categories afterwards and have them have those fields. So when you create or move a new cat under the parent there is no way to create those fields again for instance. It is all done on the initial creation of the field.
So if you move photos into other categories that data would not be transferred. It has to do with how the data is stored in other tables and arrays and such. There are limitations because of how the data is essentially stored in other tables so moving alot of things around are not a good idea when using that system of fields like the main 6 extra fields which are stored in the photos table for each photo in the same row with all the other photo data.