For my first Publii site I did set its site language to German. After creating a second site and setting English (US or UK) as its language the spell checker in the WYSIWYG editor still uses the German dictionary for this new site. Things I tried but didn’t make a difference:
- Closing and reopening Publii
- Switching the site settings from US to UK English and back
- Switching to the German site and back to the English one
I always end up with the German spell checker being used.