When writing in a book & quill, if the profanity filter is triggered, the text of the page you were editing will be completely blank. I suspect this bug is specific to Nintendo Switch, because the banned words match Nintendo's list rather than the minecraft lists. See MCPE-164987 for a list of words which trigger this.

Steps to Reproduce:

[Step 1] Write some text in a book & quill that does not trigger the profanity filter, such as "Goals:" The text should be saved as usual.

[Step 2] Write in the book again and add something that will trigger the profanity filter, such as the word "kill". I've added: "Kill the ender dragon"

[Step 3] Attempt to save out of the editing dialogue.

Observed Results:

The profanity dialog will be raised and the book page will be completely blank.

Expected Results:

Text should be saved with the offending word redacted and replaced by ####. Note that obvious profanity such as curse words are correctly redacted on signs.

Notes:

This makes it extremely frustrating to attempt to use the book and quill because you get no specific feedback on what the offensive word was, and you can lose a lot of non-offensive text by trial and error trying to figure it out.