If you could share this with folks my findings thus far on the Mobile B2 issue where students have reported seeing hidden grades in Bb Student.
I have Q4 2015 installed (Tech Preview version) on my test environment which has been updated to 94.8.0 for the Mobile B2.
I attempted to hide and then show Grade center columns and they are behaving properly. I don't see the column as the student in Bb Student when hidden.
I am still waiting to hear back on a similar issue with the TurnItIn Basic B2. We are only able to see the individual student grades for TII on Bb Mobile Learn and not for Bb Student.
When we update the Mobile B2 on Staging which is on April 2014 CU5, I can let you know if I am able to replicate the problem in Bb Student. I am wondering what type of assessment or assignment Teresa (or others) are seeing this on and what version of Learn folks having this issue might be experiencing.