I have a piece of 3mm thick plywood that is exactly 11.5x11.5. I refresh my xTool, add the thickness, and create a 11.5x11.5 square in the Creative Space so I can frame my output properly. The issue is, the box I made is not lining up with the board. Even when I frame it, the box is about 10mm inside my board all around. How is this happening and what can I do to fix it? 

Note: the xTool support has been abysmal. I reached out to them with a cylindrical engraving that went wrong, the letters were engraved all over the place, and they told me it was a camera calibration issue and I had to fix it. I don't have a PC so I borrowed one from a friend, installed a bunch of programs onto her computer, ran the system 5 times and it never aligned the way it was supposed to. Then they said I needed to fix the auto-measure, which was, again, something that had to be done on a PC. This time the file the tutorial had me download didn't open because of some error with some backend configuration of Windows that I had to download a bunch of other things to fix, but the xTool program kept coming back with the same error. 

 I fear I'm stuck with a dud machine and praying this isn't the case. xTool support is useless so I'm reaching out here to see if anyone can help me.