This is the intended behavior now – when changing worlds using the Pause menu you’ll spawn in the destination world at a particular spawn point (currently each world only has only one spawn point, but we’ll add more as we get more players online).
The fact that you kept your position if you switched worlds on the same server was just an accident of the previous implementation.
This would of become problematic for some future gameplay scenarios e.g. if you’ve built a locked, sealed room inside a beacon of yours, another player could still get inside by just going to coordinates (that would be inside the room) on another world and then switching to the world with the room.