It is by design. Different areas are available or not available on different trips forcing multiple trips to see and do it all. Since the jungle areas availability ant the temple area layout very each trip, heck the temple resets after you leave it, this areas are never considered explored. This is true even if your sim visited each jungle location, and completed each temple layout. So yes it is by design. Every jungle vacation the availability of locations change so you never know what you will find on that vacations, and the temple changes with each visit.