FYI, in my troubleshooting with EZVIZ with my DB1C, apparently you can update the firmware using the sdcard using .dav files such as the most recent CS-DB1C-A1-1E2W2FR_V5.3.0+build+220802.dav
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To upgrade firmware, you will need to prepare an empty SD card, a SD card reader and PC.
1. First...