Something that I feel in my mid back better than anything else is doing band pull aparts with my back on the bench while laying down. Hold the contracted position for a 2 count on each rep. Start with about 50 total reps, and work your way up to 100.
Something about having a feedback from the bench really helps with a great contraction.
Also, make sure on your rowing movements that you aren’t « shrugging » up while rowing. This is very common in people and they don’t even realize it.