Hi Don,
Thank you for quick answer but NT11.02 is still the same. When opening in desktop it shows menu icon if browser width is less than 640px but in mobile it not showing.
mBuild still saying that Hamburger image is not found because of broken path and is not copying to zip file. So I changed nettalk-ui.css in theme creating the result path and copying image on it (/themes/seven/styles/images/Hamburger-262626.png). Now it's working.
Thank you!
Best regards,
Marcos