Push notifications not appearing in notification center and lock screen?

[Android Central Question]

Ever since the latest Android update (8.0 Oreo), I have not been receiving push notifications on my phone. This is only the case with a few apps (Facebook, Instagram, Twitter, and Messages specifically). My phone vibrates when I receive the notification (does not make the notification sound even if the device's sound is on), and I do not receive the push notification in my notification center/lock screen. I get the notification, but there is no way for me to tell which app the notification is coming from. Any advice on how to fix this issue? Very annoyed...phone is a Samsung Galaxy S7.
Have already tried:
1. Checking if the notifications are turned on for the app
2. Unchecking "battery optimized" for each app
3. Resetting all settings

 

[B. Diddy]

Welcome to Android Central! Did you also try wiping the cache partition? https://support.t-mobile.com/docs/DOC-30240