Spellcaster reading spell books above their level?

I have a spellcaster who's an acolyte and I bought her the "tome of furio", an adept level spell book, in advance of her ranking up (she's more than halfway there). A little while ago I clicked on the book by mistake and the option to "study magical tome" was available (wasn't greyed out). Is this a new thing that spellcasters can read tomes that are above their rank? I've tried going to another lot, resetting her, deleting the localthumbcache and resource.config files. I do use mods and cc, but all are up to date & I've had most since before the last time I played a spellcaster. I've taken out the couple I've added recently & it still happens. Just in case it's an older mod/cc I'm going to remove the whole folder & see what happens. Thanks in advance for your help :).