My highscore in Infiniroom isn't updated in the google leaderboards

[Android Central Question]

I've been playing Infiniroom for quite some time now, but always skipped the registration part to Play Games to be able to see scores of other players. A few days ago I decided to finally register - this included downloading Play Games - but my record has yet to be written in the leaderboard.
I should note that the record was achieved before said installation.