Issues with prettify-symbols-mode

Hi. I'm new in emacs and I have strange issues with prettify-symbols-mode. When I write .org file "x", ":" and "+" converts to strange ligatures. But after i disable mode they are normal. I tried to add to config.el ​ [Prettify-symbols enabled](https://preview.redd.it/bmkam92yafi81.png?width=210&format=png&auto=webp&s=7cb5e704b9ed0f5b181371a49857f69be3ec36a7) [Prettify-symbols disabled](https://preview.redd.it/gfsj3k3c9fi81.png?width=227&format=png&auto=webp&s=976f7545eb1e3bd23e7f43f2f57ef05f15356bee) (prettify-symbols-mode nil) but this didn't disable this mode. ​ UPD:I used (ligautres +fira) and after I removed +fira everything was fine. UPD2: I don't install fonts for fira `fira-code-mode-insall-fonts` after install and restarting everything working.

`(prettify-symbols-mode nil)` enables the mode. Try `(prettify-symbols-mode -1)`. Also, make sure it isn't turned on in any of your hooks.

Thank for your reply. But now I think that I have issues with fallback font.