Same thing has happened to me!
I have been stalking EK website waiting for saver fares for J ex GLA to MEL with a ADL to PER then DXB-GLA. Fares were flex circa £3900 for Mar 15. They have a new special offer and its now £11,000 per person

I can book separately and take on board what was posted by edy4eva (thanks) as we aren't travelling onwards the same day.

It's just odd and annoying!!