Facebook Messenger App sound not working - Blu Studio XL 2

[Android Central Question]

I have a Blu Studio XL 2 phone and whenever I get notification from Facebook Messenger, I hear the default notification sound instead of the typical Messenger one. I checked the Messenger app to see if their notification sound is on and it was on. I have both the phone & video call and message sound turned on but it doesn't play when I get a notification. How can I fix this?

Also, I have an alarm sound that I want to set on there but when I change the sound to my own custom choice, it just switches back to the default ringtone.