Pomerol

Had my 250h F sport for a few months. On the HUD it has always shown the Shift Position permanently. Over the last few days it initially shows the Shift Position but after about 5 seconds it goes away and only reappears when the Shift Position is changed.
I have done nothing that I can think of to cause this to change.
I know this is not critical to driving the car would like to understand why this has happened if possible.