Consider disabling the spell checker in Text Editor
In Tails 6.1, spell checking is enabled by default in Text Editor:
As much as I love spell checkers, I wonder whether we should have it enabled by default.
It also tries to check spelling in code, though it doesn't underline that many words:
When Tails is in another language, the spell checkers uses that language by default instead of English.
That said, we also have spell checking enabled in LibreOffice Writer and also matching the language of the session, so I'm not sure why we would have it in LibreOffice and not in Text Editor. Maybe because it's more likely to be used for non-human languages?