Woke up this morning and all 7 of my Kasa Switches are offline. They shop up as offline in both the TP-Link App and my Smartthings app. All other devices are up and communicating. Currently all laptops (2), Smartwatches (2), iPhones (2), Roku (2), Ring Doorbells (2), various Echo Devices (3) and Ecobee Thermostat (1) are all connected and operational. Why just Kasa?

Reboot of router (Xfinity) brought all Kasa devices back. What happened?