Welcome to the forum.
What you see in Organizer, and in some other viewers is a metadata instruction set. The image has not actually been Rotated, i.e. the pixels have not been altered in any way. Open the image in PSE, PS, or any image editor, and do the Rotation there. Do a Save_As, and Import the resultant file. PrE needs for the pixels to be altered.
PS - you could adjust the fixed Effect>Rotation in PrE, but the quality will be better out of PSE (or other), and the processing of the Rotation will add overhead, when you go to Share/Export.
Thanks, Bill. That worked.
When I first used Adobe Bridge (back with CS), I got hung up on the same thing. Hey! Didn't I Rotate that image? Luckily, I found the reason, and the "cure" easily. Apparently, I was not the only person to hit that.
Good luck, and happy editing,