Exactly that. Sorry, I couldn't remember what it was called.
You have to continue that some more times. Just go to the teachers room again and do the scanning again. Afaik you have to do that 4 or 5 times in total. Didn't count but it continues after that.
There's a severe lack of hints inside of some missions, yes, but you can always visit the recollection room to get some hints for various missions. If you need other help tho, you can always ask here. I (and all of the others) will try to help as good as we can.