Olympus and Fujifilm use different methods of using manual settings.
I suggest you go to Page 43 of your Owners Manual and read.
Especially read the last paragraph of the page.
You may need to press the shutter button half-way down to see the change you made.
I have this camera and turned it to S, A, and M on the dial and have no control over aperture or shutter. And am using the command dial do change these. Can there be some sort of auto lock on it?
Am in my house with moderate light and my point and shoot Olympus could change the settings like that.