Yes, that is the solution. DxO allows to show more of a picture after distortion correction than most other RAW editors. I bet that crop settings are different in this installation between PL3 and PL4, perhaps a difference in the default preset.
I put both in layers in Affinity and they are nearly identical but the crop:
So no defect, just DxO revealing that this lens is near its limits.
Also I agree that this is not the usual vignetting which can be corrected. It is the limit of the image that the lens projects onto the sensor.