Svar från LEGO® SHOP
17 May 2019
Emily, Customer Service
Thanks for your review, and the photos! They're a big help.
Looks like that tile might have just been a little out of place from where it should be. Take a quick look at step #2, and you'll see that the gray piece should line up with the two white plates on the sides. Your build had the gray piece sitting behind those two side pieces.
If you need a further hand troubleshooting the build, get in touch with our brick experts at LEGO.com/Service.