Could not load file or assembly 'Facebook.Unity.Gameroom' Exception occurs on IL2CPP build.

We are getting the following exception while running our game on Facebook Gameroom and calling FB.Init() function.
We are using Unity 2019.1.8f1 and IL2CPP build. If we use mono build this works fine but we want to use IL2cpp only.

FileNotFoundException: Could not load file or assembly 'Facebook.Unity.Gameroom' or one of its dependencies at System.AppDomain.Load (System.String assemblyString) [0x00000] in <00000000000000000000000000000000>:0 at System.Reflection.Assembly.Load (System.String assemblyString) [0x00000] in <00000000000000000000000000000000>:0 at Facebook.Unity.Gameroom.GameroomFacebookLoader.get_FBGameObject () [0x00000] in <00000000000000000000000000000000>:0 at Facebook.Unity.FB+CompiledFacebookLoader.Start () [0x00000] in <00000000000000000000000000000000>:0
We have verified that Facebook.Unity.Gameroom.dll is getting copied to Library/PlayerDataCache\Win\Data\Managed folder but this exception still occurs as soon as game calls FB.Init method.
Let us know if someone knows what causes this issue or any fixes for the same.