Vertically maximize a window. Then resize it. The shadows disappear. If it is resized again, they reappear. Seems to have been introduced very recently.
Git commit b97d9ad681e9e60ed1a296c01c1d4328f090c659 by Vlad Zahorodnii. Committed on 18/11/2019 at 14:05. Pushed by vladz into branch 'Plasma/5.17'. Fix the order of arguments passed to changeMaximize method Summary: Related: bug 413424, bug 412888 FIXED-IN: 5.17.4 Reviewers: #kwin, davidedmundson Reviewed By: #kwin, davidedmundson Subscribers: davidedmundson, kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D25366 M +1 -1 geometry.cpp https://commits.kde.org/kwin/b97d9ad681e9e60ed1a296c01c1d4328f090c659