Thanks @mbod for your informations!
I guess I found the problem.
The dconf key “next-applet-id” (dconf-editor->cinnamon->next-applet-id) is the source of the issue.
Its value is “0” on clean installation and it must be “12” (number of installed applets plus one).
Change this solve the issue.
By the way, I’m not waiting for this anymore, it was one month ago. I’m using ApricityOS Cinnamon that’s working fine out of the box.
Some devel to address this (to other Cinnamon’s users)?