So I have an odd problem. At the end of the season last year I purchased a boat and trailer from an older guy. He had the title for the boat but no info on the trailer, but it's obvious they're a match set (Identical color scheme and same build year)

In order to transfer it to my name I need the VIN. I managed to find what was left of the VIN tag and was actually able to read most of it and I decoded the rest using the NHTSA website.

My concern is when I check that VIN it shows that the trailer has a straight semi/ semi trailer type connection. Obviously this isn't the case as it's just a standard ball hitch. I know my VIN is right based off the 9th "check digit" (which was thankfully clearly visible) matches the rest of the VIN.

With that being the case, why is it shown being classed that way??