@L3,
If in your listing you add french as language and translate description into french (in your kiwi listing) it's absolutely normal french guests could only see it in french. It always shows in guests language when hosts have it translated.
If guests language is not one you add they will see it in the original language: english. At any time you could see how guests will see it by changing language at the bottom part of main site page. I can see your listing in french if I'm logged with my french account and/or in english with my partner account.