Hello: I can’t try your file at this moment, as I am far from my computer, but would that be an issue related with mine maybe?
I changed the sample rate to 44 kHz in the intern audio device in my PC, in Dorico too, and after that I could hear correct stereo. Before that I heard in mono but at some random times the notes above a specific one in Violin 1 sounded with a weird stereo. Maybe the artifacts of just your tenor have to do with something similar.