Sometimes this happens when the nail plate is being prepped a little to vigerous..........
Removing shine should be only once in direction of nail growth, using a soft 240 koala.........
If you do this more then once, during your prep, you will remove nailplate and this will be thinner then the regrowth area........So hence once you come to soak off fabric# you will see a nice arched look where the fabric# has been.............
HTH