Not a Linux user but what version of Linux Firefox language version are you using? That way other whom are more experience with different version can see what is going on here.

I'm using Firefox 116.0.3 (64-bit) (Mozilla Firefox Flatpak mozilla flatpak - 1.0)

And I'm using Korean Language Pack 116.0.20230815.173142 (Last updated at 2023-8-18)

Hi

I am thinking there might be a problem with the Korean Language Pack, so it might be an idea if could install the Korean version of Firefox Desktop from:

https://www.mozilla.org/ko/firefox/all/#product-desktop-release

Before running it, I recommend that you take a backup of your Firefox profile (remember to do this with Firefox closed). This guide will help:

https://support.mozilla.org/ko/kb/back-and-restore-information-firefox-profiles

For help running the Korean version of Firefox Desktop, this guide might help:

https://support.mozilla.org/ko/kb/linux-firefox?redirectslug=install-firefox-linux&redirectlocale=ko#w_mozilla-bildeuro-firefox-seolcihagi-jeonmungayong

Does the Korean version of Firefox have the same issue that you were experiencing?

@Paul Problem is completely solved!!!!!!!!!!!!!!!!! Thank you so much and god bless you Paul♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡♡

Hello Paul,

I'm using Fedora Linux 39 and seeing the same issue. Before updating to the Fedora 39, I was very happy with firefox. Unfortunately, with Fedora 39, I started seeing the same issue and the solution explained above couldn't help me out. This issue is very annoying when posting my articles in Korean on firefox. Please help me not to go back to chrome browser.  :'( Thank you.

Does it still happen with the flatpak version?