HA is unreachable after rebooting the router

Hi all,
I have a problem with my Home Assistant (hassio) using duckdns and SSL.

Once I reboot the router all devices correctly reconnect to it but home assistant not and is unreachable forever until I reboot the raspberry.

Raspberry is connected via cable to the router.

What can it be?

Please help

Just a guess. If you are using the Hassio HassOs image I had issues with it randomly losing network connectivity. My solution was to install Hassio on Raspian Lite.