The issue of beacon issues with the Kukai app has been reported for over a year. It was much worse before, but now it seems to be running much smoother. We are not seeing any issues with login, so it seems like the issue has been fixed. However, if you are still having problems, make sure you are not running any extensions or firewalls that might be blocking the Google OAuth popups. This could be causing the issue and preventing you from logging in.