Expression maps limitation

Cubase lets define only 27 slots in the expression map.
Define the 28 slot and the articulations in the controller lane - disappear !.
Delete one articulation in the expression ,aps and the articulations n the controller lane appear again like magic…
Please fix that limitation

There is no such limitation.
You are talking about Key Editor, right?
In this case, vertically widen the controller lane zone till the articulations appear again.