Dragging a BP variable into a category can produce inconsistent results

The drag-onto-category operation is assigning the prettified category name, not the actual category name, resulting in variables that are not actually in the same category, even though they appear to be.

1) In an actor BP, create two new variables (NewVar_0 and NewVar_1), and expose them to instance editing (eyeball icon)

2) In Details panel, assign NewVar_0 to a new category, "NewCategory" (note no spaces)

3) In MyBlueprint variables list, drag NewVar_1 onto the "New Category" category heading to move it to the same category as NewVar_0.

4) Compile your BP

5) Place an instance of your actor into a level.

Note that the category for NewVar_0 is "NewCategory" (no space) but the category for NewVar_1 is "New Category" (with spaces). This is most problematic when editing an instance, as the two variables will show up in different category headings in the details panel. The MyBlueprint tab handles this transparently.