If the shop had several units and were selling them as new, my gut assumption would be that they ordered a bunch of cheap, garbage ones sourced from Ali Express. I’d ask the shop, because I think VGP and this one guy in Australia have been the only proper sources for new OSSCs.
Beyond knowing where it was sourced from, I think it’s kind of hard to tell. Someone else might be able to provide a better answer, but you might be able to get an idea by getting a good look at the PCB, or sharing clear photos. If the board looks dirty, or the solder looks like it’s corroded or hazy, or someone can confirm the components used aren’t correct–any of that would lead me to believe that it wasn’t sourced from VGP.