No stains before washing but stains AFTER washing.

This has been happening a lot lately. We will put something in the wash that doesn’t have any stains on it then we will wash it and dry it and then all of a sudden there are what looks like oil stains on our clothes.

We stopped using those little detergent packs and just use liquid detergent and the washing machine and dryer both appear to be clean but it’s still happening.

Has anyone else experienced this or know what is happening and what we can do?