spider mites??
are there any new leaves that are
growing in a curled twisted formation?? You can tap on the top of a leaf
any leaf with damage hold your other hand
Under the leaf,, If little black specks are in your hand after tapping the top of the leaf you may well have spider mites.
at which time if you determine they are spider mites you'll need to remove and destroy all leaves that are curled or twisted.
you can spray with a water hose full force to blast off the spider mites upper and under the leaves,, then spray with a water mister,, fill with water, and 2 teaspoons of lemon joy. and shake and spray upper and under leaves,, several treatments may have to be done untill all signs of spider mites are gone.
I have sometimes had to resort to using Rubbing alcohol and wiping down all leaves with either a q tip or cotton ball.
I'm not familiar of any other treatment or any other insect or disease that would cause this,, I'm basing your description on what I have experienced on my Brugmansia,, normally this occurs in hot dry weather.
Other members may suggest other options,,, or know exactly what is going on with your
potato leaves