Hi @Work_At_Win
App Bridge 4.x no longer uses the Provider or manual host config. Instead, it relies on the App Bridge script loaded via CDN and the API key in a meta tag. The host is automatically managed by the script and is only guaranteed to be present on the initial load of your app.
This means that you must preserve the host param on all navigations within your app.
Use the navigation API or ensure your own navigation logic always includes the host, and avoid using plain anchor tags or navigation methods that drop query parameters.