1. When Discover is installing a package, the "installed" menu item on the left panel changes to "installing", but clicking on it displays installed applications rather than applications in the process of being installed. 2. When clicking on "Tasks", the only possible way to close the dialog is to click in the grayed-out application listing area. Clicking on the left-hand panel does not close the dialog. 3. Scrolling is not always smooth and has inertia that would be only expected on a mobile device. It feels strange when using a mouse, where you expect the page to stop moving when you stop scrolling.
More: 4. There are no right scrollbars. The only way to move up or down the page is with a scrollwheel. This is inconsistent with the rest of KDE applications. 5. A KWallet dialog pops up nearly every time I open Discover. This didn't show up until I made a PGP key and set up KWallet. Why is it needed?
6. The system tray icon does not recognize when updates are installed with pacman, even when clicking the "Update" button and allowing Discover to realize that there are no updates available.
This article lists a large number of other UX problems: http://www.ocsmag.com/2017/03/29/discover-discover/
Can you please break the issues in different bug reports so each issue can be addressed separately? FWIW: 3 will be fixed with the next Kirigami release