So I managed to connect to the Rpi using CLI (MobaXterm).
I did two tries, typing “yunohost tools postinstall”:
First try, using a domain that I own:
“Error message:
Error: The domain already exists”
It seems the device is somehow registered with that domain, but the postinstallation is not complete anyway.
Second try, using a nohost.me domain that I believe is not taken:
"Error: Unable to reach DynDNS provider dyndns.yunohost.org: either your YunoHost is not correctly connected to the internet or the dynette server is down.
"
But I don’t think it is down!
I’m considering reflashing the image and going straight for the CLI.
BTW, I found one other similar support topic here describing similar errors, however here the CLI solved the issue: