Expeditions have way more bugs than standard play, which is a bit of a shame. I had to exit the Fishing expedition because my save file kept freezing, gave up on Expeditions ever since, which sucks since I finished the first twelve.
Keep in mind though, multiple bases built over the same area may not be trolling- other players may not even see your base when they're building theirs, until they log back in to find a base on top of their own; that's what happened to me on Expedition 12