Consider to post a photo of the underside of your model. Also, it would be useful to know if you have a level, calibrated bed and how you perform that task. I don't know enough about the CR10 to be specific, but 3D printers all have common requirements. Your slicer could be spot on with the preview, but if any of the settings are incorrect or inappropriate for the printer, you'll get unknown results.

What layer height are you using? What printing speed is the slicer sending to the printer. Are you using PLA? It's likely that you are, what temperature is your hot end and is your bed heated (to what temperature?)

Have you observed the printing for those first layers? That's pretty critical information omitted from your post. Consider to record a video of portions of the first layers being printed, in focus, as clearly as possible. If you're going to use a phone to record the video, hold it horizontally to get more information visible.

Fill in as many of the blanks above as you can and let's see where it goes.