When a project's breadcrumb is sufficiently long, its container partially covers the workboard columns. I've managed to reproduce this in Firefox and Chrome.
To recreate:
- Go to the workboard of a project with a long breadcrumb (e.g. WMSE-Wiki-Loves-Earth-2017 (Cooperations)).
- Make sure that the window is wide enough to show columns, but narrow enough to add line break to the breadcrumb.
Result: