What important security step did you forget to complete when setting up the new home router in the case:
While logged in to your home office router, you notice a log message describing that someone else has recently logged in to the administrative interface. This is a brand new router, and the only person you have given the WiFi credentials to is a guest that was visiting. You suspect that your guest has somehow figured out the password to your router.
This is one of the most crucial steps in purchasing a new home office router. Every router of a similar model and model has a similar default username and password for obtaining administrative connect to the device. If these settings are not changed, someone may actually "guess" the combination by attempting all of the default users and passwords for the most prevalent SOHO devices.