You should be able to read it even if not at the right level (you would just get negative moodlets). Is there any tooltip when hovering over it which would say why it’s greyed out? I’m wondering if somehow it’s not owned by the household… though even then it still shouldn’t be blocking you from reading it.
I would try dragging it out into the world, going to build mode and placing it in household inventory, closing build & going back to live mode, then reopening build mode and placing it in world again to see if that changed anything (trying to essentially reset it without cheats).
Do you have more than one sim in the household? If so, can you check and see if it’s greyed out for all of them?