on my D750, when i use off camera speedlights and i try to change flash power from the camera, my lcd screen shuts off. i've set my prefs to keep the lcd display on and this only seems to happen when i'm using the CLS and adjusting flash power levels for diff speedlights. the screen lights up and never shuts down when i shift from TTL/Manual/off settings...only when i select flash power and try to adjust them. is there something stupid i'm doing or do i have a problem with my camera ??