PXI and Instrumentation Idea Exchange

Hey Guys. I have a PXIe 5831, and am performing DPD with a thru (no DUT in the middle). I am outputting a WLAN waveform I found that at about 30% duty cycle and below, I start getting really bad EVM seemingly randomly. Looking at the spectrum produced noise all over, as well as the side band edges. The waveform just looks really bad.

With RFmx waveform creator, I have changed the dBFs backoff to 20dB, made the signal -20dBm power, and did a -15dB Runtime scaling in order to make sure that there's not something weird with the DAC being overloaded. I have also tried messing around with the power level of the Signal Generator, but it seems to occur at random power levels as well. The issue still occurs.

The DPD I tried are LUT and MP. The issue occurs with both, but seem to be more prominent with LUT.

Any and all ideas appreciated!