Automatic mail for new file within shared folders

I’m ussing NC13.0.6
I’m facing an issue regarding file sharing notification and I did not find the answer in the documentation.
Maybe there is an answer somewhere but I ran several tests and did not find a solution.

A folder is shared by User A with User B
All files within this folder are visible to A & B. It Works perfectly.
When User B uploads a file to this already shared folder in order to share it with user A, there is no automatic mail notification sent to User A saying that User B has uploaded/shared a file inside this folder.
Unless user B specifies again manually (in le share menu of the new file) that the new file that he/she just uploaded in the shared folder is shared with user A, there is no way to know for User A that User B just uploaded a new file in the already shared folder.

The first time a folder is created and shared, Users receive an email notification. Next, each time User B uploads a new file inside the shared forlder, no more news… User A does not receive anymore notification…

Question is:
Is there a way to automatically inform User A by mail that User B has uploaded an new file in their shared folder? (without specifying again directly on the new file that this is shared within th shared folder?) Because it does not work for me.

Maybe I forgot something in parameters

Thanks for your answer… and sorry if this topic has already been solved. I did not find it in the forum.