If tried to access from 'Settings', `kdesu` is used instead of `lxqt- sudo` and application starts properly. Snap attached.
** Attachment added: "Screenshot at 2021-05-28 08-51-12.png" https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1929915/+attachment/5500840/+files/Screenshot%20at%202021-05-28%2008-51-12.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1929915 Title: "Software Sources" fails to launch from Discover when tried to launch from applications list (kf.kio.gui: "Could not find the program 'lxqt- sudo'") To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/software-properties/+bug/1929915/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs