We are aware that players have issues with logging into game on android version. It is under investigation as we need to find root cause of the problem (it still works for large group of players, while it doesnt’ for others).
So far we have reports that there might be some sort of compatibility issues with Android 9.0 mainly.
There were no login procedure changes on our end for last version - that makes it a little bit more complicated as source may be with google / google games.
We will come with solution as fast as possible.