With current git master, hovering over the edge of a panel pop-up makes the pointer use the appropriate resize shape, but actually clicking and dragging does nothing; popups can't be resized. Reproduces with all panel resizable widgets, on vertical and horizontal panels, in floating and attached modes. Only tested Wayland, not X11.
Can also reproduce on X11
https://invent.kde.org/plasma/kwin/-/commit/8b7d19fdcbdb5f075e3724310242dc51e300632e might be related
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7128
Git commit 8d651f3faa073047e30290971297861c3f456f50 by Vlad Zahorodnii, on behalf of Niccolò Venerandi. Committed on 14/02/2025 at 11:26. Pushed by vladz into branch 'master'. Update isMovable/isResizable to reflect new specialWindows M +1 -1 src/x11window.cpp M +3 -3 src/xdgshellwindow.cpp https://invent.kde.org/plasma/kwin/-/commit/8d651f3faa073047e30290971297861c3f456f50