Discussion Funnel shows player stops right after gameStarted (standard events) need help stuck for months

Hi, i need help to find out the mystery here. as you can see in the image, the first funnel is the standard event gameStarted. then at the second funnel you can see that about 25% of users is dropped. during this funnel, user is prompted a login method. i offered facebook login and play as guest on android and on ios, they have additional option to login using apple signin. the second funnel, userCreated funnel is triggered after user has successfully created an account. as you can see, about 25% of user failed to create an account.

• i have tried change the game to automatically sign user as guest account, the result is still the same.
• i tried manage exclusion in google play and restrict devices with less than 3gb of ram. it seem that its not a device problem.
• i tried increased the android version requirement thinking that maybe the user with old android version is crashing. there is no crash reports and ANR in google play console.
• i also installed backtrace only to find out there is no error relates to the login section.

im really dont know what else to do now. what else are the possible cause of the user dropping during the usercreated funnel?