Something seems like it wasn't dialed in. I'm assuming the soil was nicely conductive with respect to water flow, and if the soil is dry around the carrot, it should keep telling the dripper to drip, until the soil around the carrot is wet and shuts off the flow.
You mention "the carrot was in the dry zone" and also "the side with the carrot is always moist"
it looks to me like the 'gnat condo' allows the sides to dry out too fast
weird...