A MAF reading at one point in the revs will not give you a reading to know if it is correct. What's there to compare it to? When I look at my previous data for the MAF...I see when cruising at near 3k rpm the data is between 10 and 20 g/s....not able to tell you which gear it was in etc..
What I did is dyno my car to know its HP and which specific gear it was in. Then I can, with a knowingly good/new MAF is, take the max airflow data near redline and divide the data by 0.81 to see if this matches my known HP. So, say its max mass air is 282(g/s) / 0.81 = 348 HP.
You do not need to know the actual HP. You can just check the maximum mass air data with a new MAF and no intake leaks...make note of this for future reference for when you suspect the MAF. Always do the data on the same stretch of road and in the same gear and from a full rev pull to redline. As the max mass air is just prior to redline. I have removed two previous MAFs for seeing data at 248 g/s and 255 g/s. They seem to fade into failure.
OK, moving on to the P0238 code....Typically, people find the P0238 code to be caused by wiring issues because this code refers to the signal the ECU receives from the MAP. Given you replaced the MAP, and it is the correct part, I suggest focusing on the condition of the wires and the connectors to the sensor are in place and connected well and cleanly. How to test the connection between the MAP and ECU is beyond my skill and test data is usually kept for VW tech access...might need further help if it comes to it.