Unable to select different account on google login for android

As you didn't provide any code or reference how you are logging in and logging out, it might be that you incorrectly sign out user from the app.

So here is what docs describe one should do on user logout: https://developers.google.com/identity/sign-in/android/disconnect

Sign out:

Auth.GoogleSignInApi.signOut(mGoogleApiClient).setResultCallback(
            new ResultCallback<Status>() {
                @Override
                public void onResult(Status status) {
                    // ...
                }
            });

Note: You must confirm that GoogleApiClient.onConnected has been called before signing out.

Also check status which comes in onResult - maybe there is some error, which might lead to the answer.