STEPS TO REPRODUCE 1. the connection was lost during the update 2. no update and software lists OBSERVED RESULT 'org.kde.plasma.libdiscover: last stream isn't over yet' - in console SOFTWARE/OS VERSIONS Linux/KDE Plasma: Linux kali 5.10.0-kali5-amd64 #1 SMP Debian 5.10.24-1kali1 (2021-03-23) x86_64 GNU/Linux KDE Plasma Version: 5.20.5 KDE Frameworks Version: 5.78.0 Qt Version: 5.15.2
Kali Linux runs everything as root, which is completely inappropriate for normal everyday use. I'm not surprised that Discover doesn't work properly in this situation; a lot of things won't work properly. Please choose a different distro or else get comfortable with using CLI tools to update your system,