Kay, there are certain aspects of the system that have been known to trigger some internet security systems.
Unless someone is physically hacked into your wifi or you already have a virus on your devices, it is virtually impossible for anyone to hack you on a double-NAT system such as this. There are some steps that you can take:
1. Enable MAC filtering on the wifi to only allow devices with a specific MAC address that you know about.
2. Completely scan every device on your system to ensure that there are no viruses nor any malware that are compromising your system.