The only thing in the gap seen on an SDR is some kind of beacon at around 11457.1H.
I guess this is logical because until around 18 months ago there was another Towercast group frequency active, filling this gap - at 11455H with the MPE format NRJ radio stations, which was eventually turned off because of the newer 11460.5H with 'regular' MP2 radios plus the new Métropolitain DAB+ feeds.
Before the 11460.5H frequency was active, the NRJ/Nostalgie Belgique frequency was above the old 11455H at 11458H.