wrong links

Hi, I use this wp theme
https://web2feel.com/milano-theme/

if I wrote to welcome some text with links, it shows link like this
https://www.site.com/\"link I add to my text\"

it works fine, but I had edited theme, and I don`t know when it starts.

I tried everything, turn off all plugins, upload default theme (it works fine before), upgrade wordpress ones more…. but still nothing, I really don`t know what to do. I try this theme (also my edited theme) on another wordpress blog and it works fine…
Where could be problem?
sry for english