When you change the ordering of products or SKUs fields in a category other than the main one, after clicking the sort button the changes are not saved and the changed fields do not appear after the page is reloaded.

1. From the side menu, click Catalog.
2. Click Categories.
3. Click a category that has registered product fields that were not inherited from another category.
4. Access Actions > Field (Product) or Field (SKU).
5. In the box that contains the order number, change the order of some categories.
6. Click Sort.

Currently the only solution is to perform the ordering of the fields through a Javascript customization on the front-end.