According to Canon support bulletins (ref. #TSG-IR2425-FW), the issue was threefold:
This comprehensive guide covers how to find the official firmware, execute a safe installation, and troubleshoot frozen updates or errors. 1. Where to Securely Download Canon iR 2425 Firmware canon ir 2425 firmware download fixed
Canon provides a dedicated tool that automates much of the process: According to Canon support bulletins (ref
Format a USB flash drive to FAT32. Extract the downloaded firmware ZIP file and copy the system files directly to the root directory of the USB drive. execute a safe installation
Go to Settings/Registration > Device Management > Firmware Update (or Update Firmware depending on the software version).