Message to the followers are displayed in the notifications but not on the activity stream

Message to the followers are displayed in the notifications but not on the activity stream.

Steps:

• Activate activity stream
• Makes U2 follow U1
• Turn on the message stream notifications of U2
• With U1, send a message to the followers from the dashboard
• Check the notifications of U2, the message is displayed
• Check the activity stream of U2, the message is not displayed