New Homey Pro 2023 goes offline with lan cable

Additional, are you sure Pro 2023 is

  • not on wifi only?
    The ethernet must be connected in one specific way:

  • not on LAN ánd wifi?
    With f.i. Android’s Fing app, or non-commercial Ning app, you can view what’s online in your LAN.

Are you sure Homey goes actually offline, or do you refer to the app message "Homey is offline, reconnect… "
You can install NetScan app, to let Homey ping your router, so you can log when H is really offline