You may find that HTML code is displaying in your Announcement.
Code such as <br> appears when it has been added directly to the message content:
When we look at this in the 'Code View' we can see that it is being recognised as displayable text i.e '<br>' and as such also displays in an Email.
To resolve this you'll simply need to add the <br> to the 'Code View' rather than the actual message content:
Once this is updated you'll notice that the code no longer appears in the Email body.