Hello @Olivia,
add _underline in the column names, please: constraint_message.
For example: constraint_message::Français (fr)
(In general, KoBo column and variable names do not have spaces).
See also examples in KoBo Help Center Adding Another Language to your XLSForm — KoboToolbox documentation
and in XLSForm documentation XLSForm Docs
A bit strange that it works with space (and one : ) in Enketo and the Online validator doesn’t give a warning for that.
You can also add the language code (fr) …
For codes see: Language Name and Code - #3 by wroos
