I am trying to make digiKam my default application to open .jpg files on Windows 10 and separately on Ubuntu 18. In neither case does the OS list digiKam as a possibility when I get to Settings > Aps > Default apps (>MIcrosoft store) in W10, nor in "Open with other application" in Ubuntu 18. Image Viewer and Shotwell *are* listed, but not digiKam. The program works completely if launched first, as expected.