Not early blight, no lesions. Fusarium can get into a pot if it's drain holes touch native soil, but not if you are using a barrier. Looks like Fusarium, but the many rains tell me more likely a wind/rain borne pathogen.
Copper works great on EB, if you use it every 7-10 days, and after a heavy rain, as a preventive.
Copper does get into the internal of leaf cells, so it doesn't all wash out at all, always some stays with each leaf.
I think this is a rain carried fungus, but to be sure, see if the yellowing goes up only 1 side of the plant, also cut a stem lengthwise and look at the vascular tissue. Is it purple or brown? That is Fusarium, one sided yellowing and dark vascular tissue.
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