Using set block for variable, often returns to 0

I have used a set block to set a Variable for {corporation} and entered Apple as the variable {corporation} = Apple but quite often it does not pick this up and in testing it returns the variable as 0. It seems like it would be safer to input the company name every time manually in the dialogue but that defeats the purpose of having the Variable function as an option. Can anyone help to ensure the model always returns the name I have entered?
Thank you!