i have had this issue for some time and trying to find the work around i found it and at the same time may not be the fix for you but this is what i found out … IF your phone has the feature called secure folder or something related to it … you must disable it and you must go into your battle.net account and do a manual connect of your google account … the hearthstone game using the file system to save the much needed files to keep your game going. when the phone’s security is very tight aka secure folder your hearthstone game needs access to this and without it it cant save your log information to restore your account to the game. Please look into your phone settings in the security section and find this feature and disable it. there is no easy way to have this on and use the game. Because android would half to be re-coded to have easy folder access for games… once you do this the game will work fine … Problem Solved