Factory resetting a network device restores the network device to its original firmware version. See Update network devices firmware to upgrade the network device to the latest version.
For IR1800 devices, if Access Point (WiFi) is in use, the minimum recommended version is 17.12.1a for IR IOS-XE, and 17.12.1 for Access Point (WiFi).
IMPORTANT: Once a device is onboarded and managed by IoT OD, use IoT OD for all firmware update operations on your devices. Log in and click Edge Device Manager > Software from the Services left banner. See Update network device firmware for full details.