Don't hide primary category, when editing newly created category item (e.g. product)

When selecting another category as primary for Product catalog item - that new category disappear from Sections list after changes are saved.

[B]To replicate:[/B]

• create a new product, wherever you want in catalog
• add another category in "Sections"
• add another (non-primary) category, and click "Set Primary" in toolbar. It appears as Primary
• save product
• open it again: the category you have selected as primary have disappeared

Problem seems to be for all Catalog Items