MCL, what you describe doesn't sound like being triggered to me. It sounds like it is not harkening back to some experience in your past, but all about how your T is acting in the present. It is definitely possible to feel unhappy or frustrated with our T's behavior and responses without it being due to a trigger.

This is a great thing to tell your T. Maybe he tends to be a "glass half empty" kind of guy and needs a nudge to be more positive. Or maybe this is his therapy style (it sounds more CBT than humanistic) so that is why he chooses to emphasize what he does, and he won't change it because it is not his therapy approach.

My T is from the humanist tradition which aligns on the human potential movement of the 60s/70s. So he would definitely build on a person's strengths, emphasize the positive, etc. If your T continually does not take this tack and you want it, perhaps a T who is trained in another approach would be more what you are looking for? How long have you been with your T?

In any case, I think this is a great discussion to have with your T.