My S8+ also have it. Not sure about Note 8. But try few steps. Download a 3rd party launcher and switch to it, uninstall Samsung Experience Launcher. Then Reinstall fresh and uninstall the 3rd party launcher. See if you get it, that'll completely reset the launcher default dpi so if they intended Landscape for Note 8 you'll get it.
My Note 8 has it. Though I disabled it and locked my rotations to portrait only. My homescreen layout is best suited for portrait and looks horrible in landscape. I also use Nova Launcher over the stock one. lol
edit: it's not found in regular settings. Pinch the homescreen and you should see home screen settings. Select that and there should be an option for Portrait mode only. Make sure that's disabled and you have auto rotate enabled to get it working IIRC.
Hey @mito, could you please submit a device error log to help us troubleshoot? From the Samsung Members application, tap the “Feedback” icon. Tap the Pen icon and then submit an “Error report”. Thanks!