Zeroing not accurate - AGM Global Vision Rattler TS19-256 2.5-20x 19mm Thermal Imaging Rifle Scope

I bought this unit and liked most of its features. The only problem, and it's a big problem, is that it wouldn't properly zero. The process for zeroing is fairly simple (and lots of how-to videos on YT) but each time I moved the + reticle to where I shot, it never properly adjusted. Maybe I just got a bad one. I'm debating as to whether to get a different one to see if that was the case. This one was a no-go though.