Apostrophes replaced by '

I use a plugin for automatic posting of articles on social networks, and when I

send an article on Facebook or Twitter from my website, the apostrophes of my

articles are replaced by this:

It is possible that the problem comes from the theme, but I am not sure.

I tried to do a "search and replace" to replace this code with an apostrophe

using a "regex" but it does not work at all