Looking at some pictures, I'm not sure I'd expect that information to be printed there any longer. Can you pull out the SIM tray and see if the serial number is printed there and compare it to what is reported in the phone menus? That's where it is on my Pixel 2 XL.
I'll see if someone else on the team has a Note 8 to confirm...
If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See
this link for instructions on how to join Android Central.