This fix in r104 should mean this works properly:
reaking change: Object's 'Count' expressions are now immediately updated inside loops and subevents when new instances are spawned or created, contrary to the fact these instances do not really exist until the next top-level event. This may help fix projects broken by the last breaking change which depend on object counts in subevents, but unfortunately may again break projects which already adapted to the new behavior. Sorry - in the long run it's for the best that we make these changes.
So it's strange that it doesn't. I don't believe r105 changed how it worked. Can you post a .capx?