No connection with realms in IOS

when I open Minecraft and press play it opens the 'worlds, friends, servers' screen from which you can  open worlds and realms. But it says immediately that; 'at the moment we cannot connect to realms, We will try later'.
Haven't got a clue how to solve this.  In the windows 10 version it works fine, so I have a realm  but cannot reach it from the Ipad.