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. ... View more

This happened to my wife's S9 - yup, once you see the 'Portrait' option you do feel a little bit silly... Odd that my S9+ hasn't had the issue though - for the wife, it started after the Andriod 9 update. Anyway, many thanks for sharing and helping here!  ... View more