Book & Quill text formatting not working

Pasting formatting codes into Book & Quill no longer working. Tested both on server and in a singleplayer world to check it wasn't an isolated issue.

 

I just loaded into a multiplayer game on 1.15.2 and I tried formatting a book/quill using the § formatting codes, but they didn't seem to do anything for some reason.

Just to be clear, I definitely did it correctly, I copy-pasted "§l" in and it didn't work, then I copy-pasted "§lWord" in and it didn't work. I also tried pasting just "§" in and adding the L after it as well as trying numbers and the other codes.

I then loaded a creative superflat world to quickly test it again and still had the same problem