So use your GM powers to kick things up a notch and draw people back into the game. The current situation of people getting to know each other is good and important stuff, but if it's killing motivation, we need to move past it. If need be, different groups can work out what they want to have happened over lunchtime and post it as a flashback.

For now, nothing motivates like a concrete goal. Throw in some obstacle, adversary or challenge for the students that they need to overcome, either separately together. Once we have activity up agin, we can look to more high school RP type things happening, mixed in with those shenanigans you mentioned.