Dunning by level method doesn't move items to next level

Hello,

1. We are implementing AR 9.2 (image 20). We configured a dunning method (by level). When the dunning ran first, eligible items were placed in level 1. However, when dunning is run next time, the items from level 1 don't move to level 2 (even if the interval days have passed from the previous run).

2. Message log shows that those items were included in dunning and later deleted from it.

3. We checked that items are not in collection, dispute or small items (which would get excluded through dunning method exclusion conditions). Similarly, the customers too are not in dispute, dunning hold or collection.

Is this a delivered bug? Thanks!