You are right. A new crown should feel like a natural tooth, be right on the bite and you should be able to floss without the floss shredding or getting stuck under the crown.

You must go the dentist, express those concerns and have the crown replaced. This cannot be fixed in the mouth.

If you need a second opinion go to a prosthodontist, who is the expert in restorative, cosmetic and implant dentistry in your area.