The browser and native application can use different media support, saved settings and network paths even on the same computer.
Why this happens
A successful browser session is a useful comparison, but it does not make the native player identical to the browser. Each application can have its own supported formats, account route, saved credentials and audio output. A browser can also request media in a different way from an installed application. The same computer and internet connection therefore do not remove every software difference. It is important to record whether the native app fails to log in, fails to load lists or reaches playback and then fails.
Compare the same account route and source where that is supported, stopping the first active stream before opening another on a one-connection plan. Mozilla’s media documentation describes browser-specific format support; it is not a promise that a desktop application has the same capabilities. Keep the exact application name and version alongside the browser result. Avoid weakening browser security or operating-system protection to force a comparison. A clear difference between login, loading and decoding is more useful than reinstalling several programs and losing the original working reference.
A useful way to work through it
Separate login failure, empty lists and media-playback failure in the native app.
Compare the same supported source/account route and stop the first active session.
Record browser and application versions rather than assuming one successful path proves universal compatibility.