@OvZ 

Okay, I understand that you are unable to update the firmware on your Deco Mesh system, even though the app and web interface both indicate the update process completes successfully, but the firmware versions remain unchanged after restarting.

Here are some steps and important notes to help resolve firmware upgrade issues:

1. Try Rebooting All Deco Units
After attempting the update, reboot every Deco unit in your network and try the update again.

2. Check Firmware Compatibility
If updating via the web interface, make sure the firmware file matches your specific Deco model and hardware version. Different hardware versions require different firmware files.

3. Confirm Setup Status
Firmware updates cannot be performed when Deco is in its factory default state. Please ensure your Deco Mesh system is fully set up and operational before attempting an update.

4. Use the Official Firmware
Always use the latest firmware from the official TP-Link website: https://www.tp-link.com/support/download/

5. Downgrading Firmware
Deco generally does not support firmware downgrades. However, in some cases, you may be able to manually downgrade via the web interface (method 3 above), but not all firmware versions allow this.

6. Additional Troubleshooting
• If the update process keeps failing or the firmware version does not change, try resetting the entire Deco system and setting it up again before attempting another update.
• If you continue to experience issues, please contact TP-Link support and provide your Deco model, current firmware version, and details about the steps you've already tried.

Notes:
• You must set up your Deco before updating firmware.
• Not all firmware versions support downgrading.

If you need further guidance, you can refer to the official FAQ or reach out to support for more advanced troubleshooting.