After cleaning the Murphys Oil Soap (which we dont recommend) off the floor, have you tried the Bona Hardwood Floor Mop again? If so, and the problem still persists, you are probably going to need to sand and refinish the floor. Now, the good news is that you probably dont have to sand the floor all the way down to the wood and start again with 3 coats of poly as you did before. You can do what is called a screen and coat. This will essentially take off the top layer of finish proving a smooth, clean surface for the new coat of poly to stick to.
If you don't do this yourself, it is far less expensive for a flooring pro to come in and do versus doing a full sand and refinish.
There are products on the market in which you dont have to sand or screen at all. They are made to just go over your existing finish. If this is something you are interested in, please contact us at firstname.lastname@example.org and we will get you in touch with the company that sells this product so that you can get it delivered to your home.
Hope this helps.