Posting special char in Item Status with myopenhab.org

Hello,
I’m trying to update some item with status that may contain specials char like “è” in one of my item, but I keep getting � in my states :frowning:

The request I’m testing is

curl --request POST \
  --url https://home.myopenhab.org/rest/items/Integromat_Notify \
  --header 'authorization: Basic hey, dont look at this!!' \
  --header 'content-type: text/plain; charset=utf-8' \
  --cookie X-OPENHAB-AUTH-HEADER=true \
  --data 'è_é'

I’ve tested other content-type with not better result.
Edit : The local API does not do the same thing, I though due to the console logging char error, but the data is fine in DB

Is this possible?

Thanks a lot