I have been using the GoGuardian product on our student chromebooks for 4-5 years now. For the most part it has been a pretty solid product.
I still encounter issues at times where student devices show up as "offline" when teachers have active sessions running. The only thing I can see that is possible that students can do to cause this would be to turn the wi-fi off on the chromebook. I realize this would also render the chromebook pretty useless for that student, but it does effectively distract the teacher in doing so.
I could not find it, but are we able to administratively force the wi-fi option on our chromebooks to always remain ON?