Are you running the QEC and LOL tracking and init cals? The LOL and QEC levels are very high in your case. The other spurs that you are seeing are because of the harmonics of the tone frequency that you are sending and are expected
We are facing this issue with only one particular card. If it was due to the AD9371 settings then it should be present in all the cards. So I am doubting hardware Can you please suggest some ways to debug it.