Lwaxy
Cute but dangerous
Yeah, players used to railroads/unflexible modules can be stressful in any sort of sandbox, almost as bad as sandbox players wanting to play an AP 
Are those experienced RPGers? Which could mean they always had a railroad in front of them.
It looks like you should talk to them outside the game about decision making. I have a few players like this as well, who are usually swept up by what the rest of the group does, though, so it is not as noticeable. A few of them are just worried they would derail the story, not getting that I don't really have much planned and mostly react to them.

Are those experienced RPGers? Which could mean they always had a railroad in front of them.
It looks like you should talk to them outside the game about decision making. I have a few players like this as well, who are usually swept up by what the rest of the group does, though, so it is not as noticeable. A few of them are just worried they would derail the story, not getting that I don't really have much planned and mostly react to them.