What I'm most curious about is why you'd foliar feed Trichoderma so much. It's not a nutrient and there's no reason to coat a plant in it 2-3 times a week.

When used foliarly Trichoderma "fights gray mold, powdery mildew, Pythium root rot, Rhizoctania solani, Fusarium, Sclerotium rolfsii, Sclerotinia homoeocarpa and other problems that ruin plant health and decrease yields" but unless you're also foliar spraying those nasty things on your plants you're not going to need more than one treatment every couple weeks.

I use Piranha from Advanced Nutrients for my Trichoderma needs (mostly in the reservoir though I have used it foliarly before. I wouldn't be surprised if the frequency of your spraying played a role in your problem. I doubt quality Trichoderma would cause problems themselves, but there is too much of a good thing...