Hello Sameer
The TLB should create one STO for one truck load. It can have multiple line items in the same STO with different material and destination locations from the transportation zone.
So when you are saying it created 2 STOs one for A--> B and one for A-->C I think it created full load for each STO as per your TLB profile.
Validate the quantity of the STO with respect to floor spots or any other restriction as per your TLB profile.
Regards
Abhishek