iPhone X red dot on voicemail when I’m on Facebook

When I am on Facebook, the red dot appears on my voicemail and when I select my phone for use while on Facebook the minute my phone comes up the red dot goes away like somebody is there hanging up. And I have noticed my newsfeed through Facebook is different, but it’s only when the red dot is on my voicemail when the red dot goes away different type of newsfeed change passwords did everything for security nothing seems to help. Anybody have any idea?