Main banner doesn't appear when theme was changed

I’m working in a project that use Discourse as community and i’ll do a theme change, but a problem arose, we have a main banner on top of all pages that is linked with the actual theme then when i changed the theme it doesn’t appear. I asked to my co-workers but they, who did the original config, but they don’t remember and suggested to ask here, i know that image is storage on AWS. Have some specific config to do this?

It sounds like the banner is being added through the theme. That means that when you change themes, the banner will be missing. Instead of adding the banner directly to your theme, you can create a theme component for the banner, then add that theme component to all themes on your site.

You can find more details about this at the start of this topic: Beginner's guide to using Discourse Themes.