Hi Hasib,
Thank you for creating a post. Based on the images you attached, the Value field in Set_Var is exactly the same in both steps.
If you use @SAMHSA_ICs[1][0] in the step and execute with the option checked under Set_List, it won't find a match because both columns and rows will start from 1, nothing will start from 0.
Please double check and let me know if you have any other questions.
Regards,
Subject7 Team