Any weed killer used anywhere in the vicinity? Either your place or elsewhere?

The vapors easily move on the spray turbulence or on a breeze.

mine are VERY similar to yours...my in ground plants are fine. My potted ones look the same. I've yanked them out & replanted to no avail...repeat preformances on all replacements, so I'm guessing it's a soil issue, and I added sheep manure to my pots this year (I usually do with no problem), so I'm guessing that is the problem. Lots of other posts with the same issue going on, this year.

I would suspect pesticide drift as the cause.

Sheep manure should be very well composted before using.

I know this is a little late, but I have had the same problem with my peppers this year and I thought initially that it was P or Cu deficiency but later decided (with the help of Dr. Riechers at the University of Illinois) that it was most likely 2,4-D or dicamba damage. The key to identifying is epinasty (the leaves veins should not run more or less parallel such as in the case of grasses and should be perpendicular to the main vein). I too did not use either of these herbicides but I live near a corn field that had been sprayed by an airplane. I did not know what the plane was spraying but this is the most likely cause.

Here is a link that might be useful: The Medicinal Pepper