Cron <root@mms> * * * * root : YunoHost DynDNS update; sleep $((RANDOM%60)); ! ping -q -W5 -c1 ip.yunohost.org >/dev/null 2>&1 || test -e /var/run/moulinette_yunohost.lock || yunohost dyndns update >> /dev/null

[unmy]

the answer for that is here.
i dont know if they are connected though.