Facebook Messenger Push Notifications don't work - only come through when Facebook open

A

AC Question

Hi, recently obtained S7 Edge. Getting used to it, some advantages but also some bugs. Hoping someone has figured this out.

Facebook Messenger App: No push notifications come through when the app (or Facebook) is not being actively used. Hence have to manually check messenger app to see if there are any new messages.

I have going through all the app settings, phone settings (note: whatsapp push notifications work fine), and have reinstalled facebook and messenger on multiple occasions.

any help?