The first two digits display on the Ground Control Pro are showing the Bank number and Preset Button number of the current Ground Control Pro preset.
In 4 Presets per Bank mode there are, as the name implies
, only four Presets in each Bank... Presets 1, 2, 3, and 4. So if the Display says "03" that tells you you are in Bank 0 and Preset 3 is active.
If it says "24" that tells you you are in Bank 2 and Preset 4 is active.
This is not hiding any presets from you, they are just organized to display four at a time.
I hope that helps!