I recently deleted a number of messages on the messenger app on my phone but some, possibly all are still present when I log in to my page on Facebook.com on my desktop. Is this done by default or is it an anomoly? Does it apply to voice and video calls too? I've noticed also that people I'm no longer friends with on the Facebook app still appear as friends on Facebook.com. I've searched for the answer to these questions on the Facebook help center and Google to no avail.