Symbology with two fields - Labeling problem

[Marie-JoëlleDesgagné]

Hi everyone,

I am trying to change my label in the symbology panel (see picture below)

But when I create new features, it seems like the label goes back to the original codes. You can see that the symbology is based on unique values (two fields). I tried to save the layer as a .lyr and the same problem occured again. Can someone give me a hand please ?

Thank you a lot !