Created attachment 105823 [details]
See the screenshot please.
I'm running plasma 5.10 on Arch.
That's, well, interesting ... currently no idea.
Might have been related to the implicit size thing in IconItem? What plasma-framework version is this?
*** Bug 380958 has been marked as a duplicate of this bug. ***
FYI I am using Ultra Flat Icons (https://store.kde.org/p/1171748/ - my [bug #380958](https://bugs.kde.org/show_bug.cgi?id=380958) ).
I can confirm with Ultra-Flat-Icons
Git commit d28deb6f4ab2f9e03b90f8e257145ffd793cb15d by Kai Uwe Broulik.
Committed on 17/07/2017 at 14:15.
Pushed by broulik into branch 'Plasma/5.10'.
[Task Manager] Fix icon size in launcher tooltips
Depending on icon theme the implicit size of the icon may be huge.
Differential Revision: https://phabricator.kde.org/D6751
M +2 -0 applets/taskmanager/package/contents/ui/ToolTipInstance.qml
*** Bug 382571 has been marked as a duplicate of this bug. ***
I can confirm that this is not happening anymore.