Your plants are drowning. Have you at any stage let the pots not fully dry up. Or even moist. It looks like it's a nutrient issue. But, you wouldn't just have that issue. So, its locked out. But, imo due from lack of o2 getting into the roots.
If you have had very wet soil or feed every day. This is the case, rampant intake of rich feed with no 02 getting to the root zone.