You're looking for a firmware update for the DMHZ5350BT device. Here is some solid content to help you with that:
General "under-the-hood" optimizations make the touchscreen more responsive and reduce boot-up times. dmhz5350bt firmware update link
Just follow the steps above, keep a backup of your old firmware, and you’ll be back to seamless, high‑fidelity wireless audio in minutes. You're looking for a firmware update for the
Extract the ZIP file and copy the update folder directly to the root of your USB drive—don't hide it inside other folders. 3. The Update Process and you’ll be back to seamless