There appears to be a problem with the blueprint node: “Read Leaderboard Integer” (on Android at least not able to test on iOS). I can write to the leaderboard fine with “Write Leaderboard Integer” and show the leaderboard with “Show Platform Specfic Leaderboard Screen” however everytime I use Read Leaderboard Integer to get the current best value it always executes on the “On Failure” exit node 
This is reproducible in TappyChicken as well - it using a custom event called PollLeaderboard which also fails to retrieve the leaderboard value.
To reproduce:
- Download TappyChicken from google play
- Play online and get a high score (1 is enough)
- Quit game and uninstall it (remove the save game files from your devices using a file manager as well to be sure)
- reinstall tappychicken and start
- After it connects online check your best score - it’s 0 even though the leaderboard says your best score is >0
(you could also reproduce this by signing in and playing tappychicken on another device)
It would be great to get this fixed! Not only better for the end user experience if their device high score matches the leaderboard high score but also necessary to stop leaderboard high score cheating I would imagine!