Time ago I wrote questions using LaTeX in HTML sections.  Example:

  \(  \sqrt{{x}} \)       which is:   \ (   \sqrt{{x}}   \ )  (without spaces)
 
I used it always. However,  today I tried using them and in question preview the sqrt symbol doesn't appear 
but rather the equation  \ (  \sqrt{{x}} \ )

Recently I installed  GENERICO filter. I think that is not the problem, but I think is necessary to mention it. In fact, I did the same installation in 2 sites, Only in one I have the problem so I guess I did something else.

Thanks

MDL 3.6 installed with Softaculous