@davidkidi
There are some problems with notification, we don't get many ones. To try to avoid these problems (not always possible) try to tag the people you want to write to.
If you want to tag a person, you have to use the "at sign" (the sign you found as @ on your keyword) and the name of the user you want to tag.

The format is:

@-username

(without spaces between the letters)

To tag me, for example, the correct formulation is:

@davidesimoncini