Hi JFBUK, after you mentioned the possibilty of using the Web UI to save the radio presets, it set me wondering how I did originally. Couldn't remember. So I had a go at changing some of them using the Web UI.
Select - vTuner, Continent, Country, type of station, a list of stations should appear. Click the 3 dots to the right of the station you want to preset. A drop down box should appear of the present presets. At the top of the box it asks, "Move station name to preset" Select the preset you want with a click, and it should replace what was originally there.
I powered off and on again, and the new presets were still there ok.
Hope this helps.
Leslie.