Dyndns stop working without logs

[nse]

I'm running a pfsense box configured with two dyndns entries, one for ovh and another for he tunnel broker.
My box is beind a router and has a private ip adress.
The two dyndns configs have "Enable verbose logging" checked.

After some time, the twxo dyndns does not work anymore, and I've to edit the two and use the "save and force update" button.

Where can I find the logs for the dyndns service?