The workbench selector, either in ComboBox or TabBar mode is missing the line below the widgets, which stands out from the rest of the toolbar buttons:
This was an intentional style choice for the TabBar mode and isn't a bug. But when it is in the dropdown mode it should have the line. I'll see what I can do.
The workbench selector, either in ComboBox or TabBar mode is missing the line below the widgets, which stands out from the rest of the toolbar buttons: