Hi, thank you for your quick reply !
Yes indeed it's about the zip/unzip function in the webclient however I have new results that you may help me out.
When I do the zip of a french accented filename through Chrome on my Windows 10 laptop, I have the problem but when I do the zip of that same file through Chrome on my Macbook pro laptop, it's working fine. Both Chrome are up to date. Also, I have the same problem when I do the zip of that same file through Safari on my Macbook pro laptop.
Is there a configuration that needs to be done in the browser for it to work properly ? I will look into it on my side but if you have the answer I'll take it !