The Bug:

minecraft.used:minecraft.knowledge_book doesn't increase when using a knowledge book.

Steps to Reproduce:

• Create a scoreboard objective for tracking the use of a knowledge book and set it to display on the sidebar.

/scoreboard objectives add UseKnowledgeBook minecraft.used:minecraft.knowledge_book
/scoreboard objectives setdisplay sidebar UseKnowledgeBook

• Give yourself a knowledge book.

/give @s minecraft:knowledge_book

• Switch into survival mode.
• Right-click whilst holding the knowledge book to use it.
  →  Notice how the scoreboard doesn't increase.