Script update of public IP (WOW) : ddns-start

[BEF33]

Hi everyone,
Since a few days, my ddns-start script, doesn't update my public IP, nothing in my router's log about ddns-start. So, impossible to make WOW on my NAS Syno. I have to go to the website of "DDNS Afraid" to update manually.

Moreover I notice a lot of line in my log as following :

Feb 21 13:50:13 dnsmasq-dhcp[300]: DHCPACK(br0)
Feb 21 14:23:56 WLCEVENTD: eth1: Disassoc
Feb 21 14:40:07 dnsmasq-dhcp[300]: DHCPREQUEST(br0)
Feb 21 14:40:07 dnsmasq-dhcp[300]: DHCPACK(br0)
Feb 21 14:43:54 WLCEVENTD: eth1: Assoc
Feb 21 14:43:56 dnsmasq-dhcp[300]: DHCPREQUEST(br0)

Could you please help ?
BR