Could be a couple different scenarios going on. First thought would be to make sure the callout is within the view range on the other views. Second would be to check the "Hide in scales coarser than" and make sure its not hidden there. Both of these options would be considering the view is a live cut through the model.
Is your callout to a drafting view? If so those will not show up in other views, and must be recreated in each view separately.
Probably the least likely option but you could also check the "Discipline". Are some views structural and other Architectural?
I'm sure there is more scenarios on why its not showing up but I find its usually one of these.
And I hate to even mention this, but have you checked the Visibility Graphics setting to make sure its not hidden there?
Hope this helps. Good luck!