This is very strange, but also is your Super admin an everyday user account, or a specific isolated admin account?
Google normally suspends accounts (notification after suspension with no real info) for heavily reported spam, they will suspend a ton of accounts if your domain is sending a ton of spam, even if its not via g-suite directly. This may be the case are you sure your domain is secured?
Google normally suspends accounts (notification after suspension with no real info) for heavily reported spam, they will suspend a ton of accounts if your domain is sending a ton of spam, even if its not via g-suite directly. This may be the case are you sure your domain is secured?