I'm using Thunderbird on Linux (currently 91.x) with an additional add-on for spellchecking. As so, I don't need the default spellcheck system, and I have disabled it in main settings. However, when I write an email, the default spellchecking '''is still working''' in the composition window in message part (but not in the subject field). When look into the "Options" menu, the spellchecking is marked as disabled. What interesting, if I then activate it and deactivate again, the spellchecking feature is properly disabled. Any ideas what I did wrong, or shall I just report a bug?