Unable to trigger NIR approval from BPM task

Summary:

When a NIR is created in Item class 1,Item class 2, Item class 3.For NIR approvals,I need to setup BPM rules for NIR for three item classes: Item class 1, Item class 2, Item class 3.

Rule 1: Item.categorycode is "Item class 1" with approval group defined

Rule 2: Item.itemclass is "Item class 2" with a approval group defined

Rule 3: Item.itemclass is "Item class 3" with a approval group defined

Now When item is created in item class 1, BPM is triggering approval user

when item is created in item class 2 , BPM is triggering approval user

When Item is created in Item class 3, BPM is not triggering approval user