This depends on the default value setting of the attribute in your entity. Integer attributes get 0 as default value unless you explicitly changed it to empty (in Java null).
Hi Arthur,
I've found the same result when I didn't have a default value set at the Integer attribute. I'm also using the same version.
For me it was just as simple to set the default value to 0.
Perhaps this is a bug, can you try creating the integer attribute again?