If the mirror adjust is set to 'synchronous' in the convenience menu in the MFD then that's correct. Both mirrors will move simultaneously but only when using the knob in the R position. If you use the knob for the left mirror, it will only move the left one.
Weirdly the handbook states the opposite of this and says it's the L knob position that adjusts both but on mine it's the R position, like yours.
If mirror adjust is set to 'individual' in the MFD then you can only adjust each mirror using the corresponding knob position L or R