Strange text replacement in cells

Hi,

Today I encountered a problem which turns the content of my cells from text (containing some UTF-8 letters such as é ç à è) in a suit of special characters. It is a Sharepoint file being accessed by arround 30-40 users. It only affect some pages and specifics lines, and as you can see, the real value of the selected case is still normal, but in the grid some nonsense is displayed.

I tried accessing it from my account on my PC, I could see everything normally, but on an user PC, either with my account or his, the display was the one below:

I am sorry in advance if this problem has already been solved, I couldn't find any answer while searching for this problem.

Regards

Yann