Certified GKH Gardening Expert
Unless you, absolutely, have to water twice per day (i.e. a meter tells you that the soil is dry down to about 3 inches) I would say that it is remaining too moist without a dry out. This can cause poor nutrient uptake, or cause soil infections that will cause the soil to be way to acidic to support plant life, but allow bacteria to flourish.
I see, what looks like, the start of a magnesium deficiency. This can indicate an actual magnesium deficiency, or low soil pH.
First, I would recommend testing the pH and nutrient content:
You can amend, accordingly, once you see what the soil's profile looks like.
Here are some more articles that will help: