OK, i've actually found out this is a feature...
If your phone is set yo portrait mode and you want to rotate the screen, you'll notice a small icon appear next to the home key when you turn the phone - hit this and the screen rotates. turn the phone back and the icon reappears - hit it to rotate the screen.
This is incredibly useful for me who gets frustrated when some apps rotate and i don't want them to (yes, i know there are utilities to l;ock individual apps, but i've never found one up to my required standards )
I found this info on the Digital Trends webite.
This helped me figure it out!
Auto-rotate totally dissappeared from my shade. It wasn't renamed Panel or Landscape, there was simply one less item on the shade.
Anyway, I went to settings and searched for "rotate". This took me to Accessability. I scrolled down and found Auto-rotate screen and turned it on. Bingo! Auto-rotate is back on my shade!