Hey :) long time listener first time caller

I bought a homemade teardrop trailer on a harbor freight base awhile back. I hadn’t been able to use it all winter so I didn’t bother trying to register it until now. Here’s where it gets weird.

I bought the thing in KY, I live in IN. Guy I brought it from said he didn’t have to title/register trailers in his state so it didn’t have a title. My parents had built a trailer and had it titled with little to no issue so I didn’t think much of it.

FF to today, I had to call the sheriffs dept to come do a VIN inspection so I can apply for a title. Cop showed up, said he could see where the VIN used to be but that I had been taken off (???). He said I’d have to call a private investigator or something because he thought the trailer was stolen.

All that being said, does anyone know the deal with Harbor Freight trailers and VIN numbers? Google came back inconclusive. What do I do?