Now it’s not using jquery and it’s sticky on desktop but not mobile devices.
1- How do I also make the navigation sticky on mobile devices?
2- Why can’t I change the color of the header and the titles inside it?
3- Why the sticky slider is transparent and how to change its color?
1. You’re using the mobile header, so you’d need to add this:
2. How are you trying to? Via the Customizer?
3. When your header is merged like it is, the plugin specifically re-styles the navigation when it’s sticky to use your navigation colors. Since you’re not using the built-in sticky solution, it can’t do this. In fact, there is no way to target your sticky navigation, as it’s not using JS to become sticky, unfortunately.