Map knob setting is not synced with what is shown on MFD

[exodus]

I noticed that when I set the MFD to "map" and then use the knob to change the distance setting, what is shown on the MFD appear to be "1 click" behind. For example, if I set the map distance knob to "40" the MFD distance shows "20" (nautical miles I assume). The MFD always appears to be one "knob click" behind the actual setting.

[Poweer]

That is correct serting because mark is in the middle of the range. MFD shows 40nm with mark at 20nm. No bug here.