Duplicate Facebook notifications OK I am a non tech, old generation guy, using an HTC Android phone. Just recently when Facebook posts to my phone, not only do I get the usual tone to alert me to a posting, a split second later I get a bell sound, a bell shaped icon, and the text "xx also commented on his post https://m.facebook.com/  meaning that I have two alerts for the posting. It's only started doing this recently.

Why is it doing this (duplication) and how can I stop it (irritating!)

Thanks
It seems you have used Chrome to log into Facebook.

Go to Chrome>Menu>Settings>Site Settings>Notifications, and disable Facebook from there.