Hi
Whatever is modeled, by default it goes in Main Model / common model .
Revit has no clue whether it should belong to option A or option B...
To make sure you are working in correct option, just create Views, renaming them to correction
Design option, and keeping only those options Switched ON...
and while working in design option, revit clearly shows elements in main model ( GREYED OUT ) and editable
current option...DARK
Idea is not to model in main if there are design option consideration...and its also hard to
move object from one option to another, sometimes its impossible to move one element from one
option to other, only way hence to copy and paste is correct design option...
there is a bit of learning curve for design option, its not a straighforward stuff... its in depth pretty useful
only when you know exactly how design options behave...
simple tip... elements which are hosted, their host also should be in the same design option..
ex : Window 1 , in option A and no window in another option B...to solve this.. keep
one wall in design option B ( without window 1)
One wall in Design option A ( with Window 1)..
common mistake many people do here is keeping the same wall in both option ( main model )
and later when there are modification to that wall, there will be lot of conflicts...
Best luck
Cheers !
Corsten
Building Designer