After I add a DDNS entry in ADE-3400v3/ADE-4400v3/ADW-4401v4, why does the DDNS still not update?

After you add the DDNS entry, please click the Commit / Reboot button. The Router will restart and then your DDNS will be worked properly.
Notice: Many settings of ADE-3400v3 / 4400v3 / ADW-4401v4 need to save and reboot. So when you change or set the settings of router, please remember to click the Commit / Reboot for making these settings effective immediately.