In the Tracker class, the Tracker.getDatabaseConfig event is fired before the loading of the plugins.
So, the DB config is initialized before we can change it with the Tracker.getDatabaseConfig event registered in a plugin
In d828bca7ea58cf33932a92b39bff643290b5fee4: Fixes #4681 Move the Event to the factory so it is executed right before creating the object itself. Hopefully this works, if not please comment. thanks for report!
Thanks for this fix, all is correct with the tracker entire file. I have not the same version of the file