Why do my facebook messenger app uninstall itself?

[Android Central Question]

I use infinix note 4 pro.
The phone was giving me problems and I decided to return it to point of purchase.
Before that I decided to uninstall my facebook messenger as I couldn't sign out.
Now that I have collected the phone, whenever I restart my phone, the app disappear

 

[B. Diddy]

Welcome to Android Central! After the factory reset, did you reinstall Facebook Messenger? Are you saying that after reinstalling it, it always disappears after a reboot? Does it only disappear from the homescreen, or also from the App Drawer?

 

[Pxb]

Mine disappears everywhere