I thought I understood a bit about networking.
However I am bewildered why I can control Volumio through the Chrome browser from a Windows Laptop, but not through the Chrome browser of a Chromebook nor an Android phone.
Can somebody help me find a solution?
I think this is because Android (and presumably Chrome OS) do not resolve DNS on the local network. This is a security feature. The consequence is that you cannot use the address volumio.local to connect, but have to use the raw IP address (e.g. 192.168.1.10). It is worth giving your Volumio a fixed IP address so that you can bookmark it.