I just came across this issue. This is an FYI since it’s similar to: Unable to Change Cockpit Camera Height but for me it’s the “reset camera” that wasn’t working and how I came to find it. Hopefully this helps someone else.
A work around is to hit Esc, go into General Options, Camera, and hit reset to defaults (assuming you have nothing else set to custom). Apply and go back into sim.
That’s not a solution when you actually want your camera to be higher than the default “50%”.
The problem is that FSRealistic overrides the camera height selection, so having default settings when you’ve set something different does not “fix” the problem.