Your downlink looks good. The way to test is RSSI - SNR should equal the noise floor. You downlink fits that equation. Your problem is uplink. I suspect that you have uplink noise rise, which is a way of saying that you have interference on this end, but no interference at the other end. Solve the uplink interference, and you should have QAM64 or QAM256 some of the time if you can make the uplink signal quality the same as the downlink signal quality.