Here is what you need to do:
Go you your Facebook profile and click on the settings
Click settings then scroll down to business integrations
Inside of business integrations find the app and click on edit then click remove
Navigate back to your Dashboard.
Go to settings > Manage social media
click AUTHORIZE next to Facebook and give the app ALL permissions - make sure posts are public.
You will be all set after you do this.
Here are the scenarios where you will need to do this:
1 - If there is a warning message on your Dashboard about missing permissions
2 - If you create a NEW group or event and it is not showing up.