in the fzp file for the part (which defines the buses) there is a second bus but with non existent pins (the parts checker flagged it). It is likely a leftover from what ever part you cloned. The two ground pins are indeed bused correctly, clicking on one of the grounds lights both it and the other ground pin yellow as it should. The fzp file labels are therefore wrong as they indicate non ground pins (that will be why the labels come up wrong when you hover over them as well).
Peter