I am only speaking the true because I have done the same thing for many years with my bipolar spkrs and could not understand why. I had my sofa directly against the wall for many years, I set my bipolar speakers high and low, I also tried them as front higher speakers, nothing worked until I change my surround spkrs.
It took me such a long time to find a solution. I have told you one of 2 ways for bipolar speakers to perform properly. Another way is to have some distance between the rear wall behind the sofa.