I just tested and it worked for me. Here is a screenshot of what it did on my computer.
For the image you posted, is that the full image or did you crop off the bottom before posting the image? It looks like the left foot might be stick over the green mat. If the original image includes the foot and it is overlapping onto the wood flor then that would explain why it didn’t clear. However, for the image as you posted it, the clearing should work fine.
If you didn’t make any further crop and the image just as it was posted isn’t working then is it the only image that has issues? Or are other images having the same issue?