I had this issue, then I quit the game and restarted. Grimoires in my inventory were working but when I tried to look at ones in stores it only showed the first spell of each level of the last grimoire in my inventory I had looked at.
And yes, Archaven, I also noticed my characters moving as if they weren't stealthed and being detected very quickly, but only if I moved as a group. Individual character movements were at normal speed...