Lookup DataTable Not Found, But Index = 0

Hi everyone. I got this case, I dont know why when I lookup not found, the index return is not “-1”. It is 0

Hi @hung_pham_ngoc !
Welcome to UiPath Community :grinning_face_with_smiling_eyes:
Indeed that’s an interesting case, would you mind sending us your workflow (xaml file) and your excel data so we investigate together ? If you can’t, you can create dummy excel data and send a part of your workflow