Your file is sideways and it also has rotation flag. The rotation flag tells graphics software that it needs to rotate the sideways image before displaying it. When that happens, you don’t even realize the image is sideways.
If you are looking at the file outside of RM, the program you are using is processing the rotation flag properly.
When you convert the image to PDF, the program converting the image is processing the rotation flag properly.
When you are looking t the image in RM, RM is not processing the rotation flag properly, or more probably is not processing the rotation flag at all.
Until/unless this limitation in RM is remedied, you need to edit the file from outside of RM, rotate it and save it. Actually, on Windows I have had good luck just right clicking files in Windows File Explorer and using the Rotate option that shows up. I don’t know if a Mac has the same right click option.