With reference to the SDF-57601 : Option to configure Multiple mail Ids for requester

I've just installed the latest updates and i could add another email address to the requester but after testing, it worked once on my test environment.

However, when I tried to use it on the production environment, it doesn't work... 

The requester still gets the emails only on the primary email address.

Any idea why is that happening?

Kind Regards, 

Georges Samy