Unity Game Facebook SDK

I need a Unity game developer with knowledge of Facebook SDK integration & firebase TCP server. In my facebook developers account I have the user_friends permission, which lets me access the user's friends that have installed the game... but some of the friends that do have the game installed, are showing up on other devices that have low friend count but are not showing up on the list of friends with high friend count in my games home screen menu. I think it has to do how the game loads these friends into the list, maybe a memory issue or something related. I need a developer to fix this bug on my 2D Unity game. Please bid the amount you will charge to fix, offers that change the pricing upon messaging will not be regarded for award* Also, please provide links or examples of your previous works using user_friends permission on facebook sdk in unity.