Idk man, losing a few lowers and innards is normal with bushy ass plants because of lack of light. But a dozen per day seems like a bit much. This started happening to me and
@SuperNutz
and we both discovered root aphids in the soil. Check your soil for pests. Are you keeping ph in check in your solutions? At first it was a few leaves a day on my plants for a couple weeks and It looked like a possible magnesium or nitrogen def and then the past 3 days the entire lower half and innards on the upper part of my plants look all light green/yellow with rusty brown.