It was me and it was annoyng and inconsistent - you change something, it gets saved but you are not warned for the change.
Anyway changing visibility should not touch the element for recompute. Unless visibility properties can be referenced through expressions and are referenced.
I think that changing to real without confirming a value (pressing Ok) is wrong. But I recently used a lot this auto changing to real dimension and think it is good automation. Just not applied at opening the constraint for editing.