Put a log above the if statment & check the file path that you are using in if statment via config is correct or not.
can you check in the immediate panel whether the values is present or not
and also check this
check whether the arguments are correctly mapped for config argument or not
You’re trying to use Config in the If before you’ve read the Excel file into Config, so Config has no value yet.
Can you check in Locals Panel the current values to your variables to see if you initiate the Config properly.
and, you trying to read another sheet from your config file or this is the first time you trying to read de Config file?