Lyx. Space between letters of some words in program listing

Question

When I create a pdf document that I'm writing in Lyx, there are spaces between letters in some words when I use code programs to insert some pieces of programming.

In the Lyx program listing configuration I added the option "showstringspaces = false" but I do not get anything.

Can you tell me how I can remove these annoying spaces so that all the letters of each word in the code lists appear together?

I get ---> fmt. P r i n t

I expect ---> fmt.Print

Answer 1

I answer to myself. Putting the option columns = fullflexible or columns = flexible in the configuration of the code lists is solved