Thank you for reaching out and thanks for sharing the screenshot. I tried to reproduce the same at my end. However, it doesn't show any margin spacing when aligning the shape to the left of the artboard at my end. I'd like to know a few more details like:
Is it happening with a specific file? could you please try to reproduce the same on another file and share the results?
Sorry，I find the reason. I started using sketch to do this project, and then converted from sketch to XD and continued to do this project. But I copied the content into a new file and the problem was solved.