Styracosaurus charge icon turns black, mouse cancel disabled but hotkey cancel still works

Near the end of Styracosaurus's charge, the skill icon turns black. It cannot be cancelled by mouse click, but can still be cancelled via bound hotkeys.

When the charge is nearing its end, the skill icon becomes black and unresponsive to mouse input. Hotkey bindings still work to cancel the charge normally.

The icon should not turn black near the end of the charge, and the charge should be cancellable by mouse click.