pk_testimonials

Hello everybody!
Using an Alysum template, I am currently facing an issue since the beginning, even if I update the template.
When customers write testimonials, everything is fine in back office, but in front office I have a kind of UTF-8 issue, with kinds of cabalistics symbols. I was able to remove the signs causing these issues from the back office, and I can’t do it anymore.
So I would like to know ho to solve that UTF-8 issue. To illustrate it you can see 2 testimonials here.


At the top a message with issue, the second one the message when I was able to remove signs causing the issue.

Do you have any ideas of how to solve it?

Many thanks!