Can't update our game subcategory from app basic settings

The review section stating that subcategory not selected however we did choose and saved the settings .. and due to this issue we can't submit instant game updates for review. As we can't proceed without fixing this issue .

Clearly this is a bug and it's been around for the past months but and now due to this the submit button is always disabled at instant game submit for review section

Attach video show how subcategory not saved even after we clock on the save button.