Problems using KDE Connect Browse device to access phone from Windows

I am trying to use KDE Connect and Dolphin on a Windows PC to browse files on a phone. I can connect and send single files and clipboards both ways, but cannot find how to browse files on the phone. Selecting “Browse device” from the KDE Connect task bar icon just opens the box:

    You’ll need a new app to open this sftp link
    Look for an app in the Microsoft Store

with no other option. I presume it needs to open Dolphin, but can find no way of doing so.

Alternatively, in Dolphin, selecting Network and entering an ip address (sftp://nnn.nnn.nnn.nnn) shows the status message:

    Opening SFTP connection to host nnn.nnn.nnn.nnn        Loading folder…

followed some time later by:

    Loading cancelled        Timeout connecting to host nnn.nnn.nnn.nnn

I have spent some time looking for information and advice on this, but have found very little.

Should this be possible and if so what should I be doing?

The features I can use are useful and work well, but I would like to get browsing working.