XGBOOST regression prediction and orignal sub data set offsetting

Hi, I am using predicting using XGBOOST but my prediction and simulation results for a smaller dataset is not overlapping one another. could it be a scaling issue? i tried playing with hyperparameters in xboost and they are affecting only the y axis… the x a xis offset between predicted and simulated results remain

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Try setting base_score parameter to 0.