text dosent align on book (crashes)

I was playing Minecraft on a dissent sized server then I was righting a book and quill, but the flashing line that usually appears did not align properly with where I was actually typing (it was a few letters behind but wasn't consistent), then I decided to click on it do select exactly where I type then it crashed (it said text out of bounds on the launcher)

in the image you can see the _ under a letter it's supposed to show up as an l if it's in the middle but I'm actually selecting the last letter of this book