In both git master on Neon and 5.14.3 on Manjaro, I can reproduce the same issue: when updating PackageKit packages, The global progress bar stays at 0% until completion. If you click on the progress display entry, it shows a progress bar with the text "Waiting - 0%" for the entire duration fo the update operation. Individual packages' progress bars intermittently fill up, but it's not reliable the way it used to be.
Git commit 119c3ffcba622cbc136ec0adcea8b7518379aed2 by Aleix Pol. Committed on 13/11/2018 at 15:08. Pushed by apol into branch 'Plasma/5.14'. Fix global progress display for updates M +1 -1 libdiscover/resources/ResourcesUpdatesModel.cpp https://commits.kde.org/discover/119c3ffcba622cbc136ec0adcea8b7518379aed2