Problem with NavMesh Baking

hi
following the courseware chapter about navMesh, i can't seem to get it to work properly
there are holes as expected around the static objects (toys, drawers, etc) but for some reasons , almost every whole is duplicated with some offset. please check the attached imagehttps://drive.google.com/file/d/1oORngff-78TZ-z29-ig-fz2gFAcC6Xxt/view?usp=sharing