We are having to use the deep fill option more than I’d like. We have 2 dogs. Our sofa is covered with a flannel sheet and a plain cotton sheet. The sheets are changed 
every 2 days. The flannel sheet gets put in the washer first. It has come out in f the washer with hair and muddy footprints - just like when I put it in. And the sheet is dry in those places that are still soiled.  I shake out everything before washing. Always have.  I have found if I don’t use deep fill the problem persists. We don’t have muddy footprints everyday but you can tell the sheets aren’t clean. Im not happy. It makes me worry what else is still dirty but just isn’t visible.