Investigating - We recently identified an issue that can break communication with secure Z-Wave devices (e.g., locks) after performing a soft factory reset on 2015 and 2018 model Hubs running firmware version 25.26 and above. This soft factory reset, also known as a firmware flash, is initiated by holding the red reset button and releasing after approximately 15 seconds when the LED is rapidly blinking yellow.

Support may have recommended this as a troubleshooting step in the past and under normal circumstances only re-downloads the latest firmware without impacting devices, but we recommend against performing soft factory resets while our teams investigate a fix.
Apr 11, 20:27 EDT