I think your res temp is too high.......
Water quickly become anaerobic (oxegenless) or stagnant when the res temp is too high, meaning your roots are starving of oxegen, when roots are starved of oxegen your plants can present symptoms like that, almost looks like overwatering in soil, which is a similar scenario when excess water being held in the soil cannot be uptaken quick enough by the plant and the water becomes anaerobic around the roots starving them of oxegen and then wilting like that, high res temps are also an invite for root pathogens and bacterias. Im pretty sure high res temps can lockout certain nutrients aswell and give you inaccurate ph readings.