watchfacebuilder not installing

I've had a replacement 965 and before had several watch faces on it from https://garmin.watchfacebuilder.com/?screensize=454%20x%20454 - I've re-downloaded the ones I wanted and used a backup copy of the prg file I originally had but now one of them install or appear on my new 965.

Does anyone else use them and find they won't appear? You can just download any from https://garmin.watchfacebuilder.com/?screensize=454%20x%20454 and copy the .prg file from inside the .zip file to /garmin/apps on the watch. I'm using the latest stable/public firmware and wondering if, coincidentally, it's something which has changed with the newest fw