I found some more useful logs: [enocean] Gateway doesn't issue updates (but it does send commands) · Issue #17693 · openhab/openhab-addons · GitHub.
There’s an error mentioning ThreadPoolExecutor, so I assume it’s got something to do with multithreading…?
@Beasty, progress is made to tackle this problem: [enocean] Gateway doesn't issue updates (but it does send commands) · Issue #17693 · openhab/openhab-addons · GitHub
Maybe you can add some (logging?) value or perspective?