Welcome to the Bose Community Forums! I'm delighted to hear that you're enjoying the audio quality for the Home Speaker 500, but sorry to hear that you're experiencing issues with the Bose Music app.
The Bass audio adjustment setting within the Bose Music application for your speaker is still active and a feature - you may be running on an outdated Android app version. Our current version is 1.7.2 for iOS and Android, and as such if your application has not automatically updated it may be beneficial to uninstall and reinstall the Bose Music app from your device.
If this does not resolve the issue you're currently experiencing, please advise me accordingly and we'd love to investigate this further.
Andy B - Community Support
This is a known fault that our team is currently working on. The Bass adjustment is actually controlled by the 'Speaker level.' It is unknown why this was renamed before the latest firmware update, but will perform the same function as the Bass adjustment level that preceded it. It will be renamed and corrected in an upcoming update.