there is a random "[" in my libreoffice word document and it's not a character so i can't backspace it. How do i remove it?

A screenshot of the thing might be helpful.

Is it a field (does it have a grey highlight)?

Can you go to the left of it (by pressing home etc.) then press delete?

I've been using Libre office exclusively for a few years and don't remember encountering strange unremovable characters.