This seems like an odd problem.
I don't remember
1. What lighting are you using?
2.
nutrients and the concentrations? (were you able to contact the manufacture to find out what they recommend for continuously fruiting plants?)
3. light and water cycle?
4. Are you sure that the
nutrient temp is staying within that range all day long and not fluctuating higher?
5. Air temp?
6. How do the roots look?
7. How does the nutrient solution look, is it clear cloudy?
8. how often do you change the nutrients?