[27.0beta] Wrong app shown as running in Background in Dock

I develop a tool on macOS which is composed of an UI app to manage the main app settings, and an Agent that runs in background doing some tasks ?

(Running the agent is optional, can be launched from the UI app, and can be launched by macOS at startup with SMAppService. )

Agent has the LSUIElement flag set, and only shows a Menu Extra (or whatever it now named), and sometimes some notifications.

The whole App package is bundled this way MainAppUI.app/Contents/Library/LoginItems/AppAgent.app (for SMAppService to work)

This has been working correctly for years

Now on macOS 27 beta, once I quit the UI App, having launched the Agent, the Dock reports the UI App is still running in background (with the grey dot) . But only the Agent is running, not the UI app process.

Moreover, System Settings->Background apps reports both the UI app AND the Agent as both requesting to run in background.

I would have expected only the Agent being listed in System Settings, and nothing appearing in the Dock.

Is this a bug in the OS beta , showing the top-level container bundle as the app running in background instead of the executable direct container ?

Or maybe it's on me and I should bundle my app differently ? (I cannot "reverse" the bundle and put the Agent as the main app, with UI "inside", as double clicking the main app should launch the UI App , not the Agent. )

BTW, filed FB23203848 for the same subject.

thanks for any direction