I've been growing okra the last three years in my Earthbox containers as well...
I've been growing okra the last three years in my Earthbox containers as well as in the ground, but never had the leaves look like they were sick. Here's two pictures of the sick leaves and notice the peppers in the same container look good. What's going on?
This looks like environmental injury to our vegetable specialist. There is no recognizable disease damage and only a tiny bit of possible insect injury (the holes.)
The injury could have occurred to the plants before you planted them, or the okra may be more sensitive than the pepper to the environmental situation, such as temperature swings.
We do not recommend any steps at this time.