I play on PS4, NA servers. After completing the quest where you can either burn the books, or give them to the Khajiit, there is a small bandit camp located near the shrine. In this camp is a note, which reading will start the Hazaak Hollow quest.
On two separate characters now, after leaving the shrine and reading that note, the ability to block completely stops functioning. I can block before reading the note, but not after. Weapon swap does not fix, neither does roll dodge. The only working solution has been to log out, and log back in.
I reported the bug through the in-game menu.