Pixels missing in the display is quite common for these models and usually does not impact the operation of the vehicle, although it is distracting. The replacement of the instrument cluster is the only thing I can recommend to fix this issue. The replacement cluster will require proper coding and can be completed by the dealer or an independent with the proper software. You may wish to deal with this issue as it is now. The cluster replacement cost isn't cheap, maybe as much as $700, then its installation and coding costs.