No sound for Messenger notifications on iPhone

I have done everything I am supposed to do and I am still getting no sound when someone tries to notify me on my messenger app, I am not the only one some other people have said they no longer have sound on their notifications

Since my phone was last updated I am no longer receiving sound for my notifications, this is how I make a living is through messenger and there are no sounds telling me that I have a message, why?

[Edited by Moderator]