My RUT950 is on 05.02.6 - since this update dyndns is not reliable. DDNS interval is set to 10 minutes, and DDNS updates are sent after periodic reboot of router or manual reboot of DDNS-Service (so configuration seems to be correct). But after router gets a new IP (i.e. after restarting LTE connection), DDNS-updates are not sent until the next reboot of DDNS-service?