Hi Roscoe17,
For help with iOS notifications, test checking and adjusting your settings with the steps below found in the article here: Change notification settings on iPhone - Apple Support
"Change notification settings
Most notification settings can be customized for each app. You can turn app notifications on or off, have notifications play a sound, choose how and where you want app notifications to appear when your device is unlocked, and more.
- Go to Settings > Notifications.
- To schedule a notifications summary, tap Scheduled Summary, then turn on Scheduled Summary.
- Select the apps you want notifications for in your summary, set a time for delivery of your summary, then tap at the top left. (See schedule a notifications summary.)
- To choose when you want most notification previews to appear, tap Show Previews, select an option—Always, When Unlocked, or Never—then tap at the top left.
- Previews can include things like text (from Messages and Mail) and invitation details (from Calendar). You can override this setting for individual apps.
- Tap an app below Notification Style, then turn Allow Notifications on or off.
- If you turn on Allow Notifications, choose when you want the notifications delivered—immediately or in the scheduled notifications summary—and turn Time Sensitive Notifications on or off.
- For many apps, you can also set a notification banner style and turn sounds and badges on or off.
- Tap Notification Grouping, then choose how you want the notifications grouped:
- Automatic: The notifications from the app are grouped according to organizing criteria within the app, such as by topic or thread.
- By App: All the notifications from the app are grouped together.
- Off: Turn off grouping.
To turn off notifications selectively for apps, go to Settings > Notifications > Siri Suggestions, then turn off any app."
If you use and sign into two different accounts on your device, check your Facebook app settings with the help of their support pages found in the links below.
How do I adjust my mobile push notifications from Facebook?
Choose what you get notifications for on Facebook
If you continue to have issues, reach out to the app developer. How to contact an app developer - Apple Support
Cheers.