When the taskbar is set to icon only mode and I hover over an icon there is a small delay before the preview gets shown. When I hover to the next icon there is no delay before the next preview will be shown. It would be nice if there was an option to set a delay before the next preview gets shown because currently I often select the wrong window.
The problem is also described nicely here: https://www.reddit.com/r/kde/comments/6gxmde/iconsonly_taskbar_rollover_sensitivity/
*** This bug has been marked as a duplicate of bug 358930 ***