I like to use more uncommon tools (it often bites me afterward but it’s funnier this way

I know the feeling.

How about this: docs.xcp-ng.org/installation/install-xcp-ng/#9-ne…

Try setting a static ip address on xcp-ng itself, during the install phase. (this was how devices got onto networks before dhcp). You’ll have to make sure it doesn’t conflict with anything else on the network.

Install XCP-ng | XCP-ng Documentation

How to install XCP-ng.

I did not see your answer. As per the edit : the emergency network reset solved the issue. Thank you for your answer