I was very lucky to find a solution at a very reasonable cost 2 years ago. I added a hitch to my car at a U-Haul shop and then put a platform type bike rack on it.
They did the install by the book as per factory manual as far as I can tell but within a few months, bumpy dirt roads etc.... the platform rack was less than flat or 'level'. It was not hurting anything but I didn't know if it would get worse or something would break so U-Haul went back in there to check it out. Nothing was going to get worse or break but the bracket under the car or the flange (part of the car) was titled. The gave me the name of a local welder in case there were some options or needs to pursue.
I went to his shop and together, we decided the 2" to 1.25 adapter / riser could be cut and re welded to correct the angle of the receiver making the rack flat and looking normal. He did it once and wasn't quite happy with the angle so he re-did it again before calling me. I went back to pick it up and see the results, it looked and worked great and the agreed price of $50 was a good deal I my view, I added another $10 just for good measure. Found out he is a top secret certified FAA , USAF airplane fixer - upper and welder, etc.... Super nice guy too.