Facing issue with datasource and loop iteration

I have one parent datasource and loop and also a sub-data source and a loop steps (as in attached diagram), in between I have a assertion that gets executed.

So I have a problem with sub-datasource ('VerifyDataSource') the datasource returns 3 records but iteration happens only for 2 records. 

Also attaching below b 'VerifyDataSource' property view.

Please can anyone help ?