Error when trying to change the product code

Hello, I have the essential version and when I try to change the product code of an existing product I got the error that the code is already use and dont let me save.
For sure the code I want to use is new.

If i create a new product and change(before saving) the product code, it let me save correctly.

Someone can help me?
Thank you

Perfect it's working!Thank you so much for your fast support!
Thank you