Although Philips has discontinued the SPA5210, official resources are still available:
Philips does not provide a dedicated, standalone driver download file for Windows 10 because the speaker is designed to utilize the native Microsoft generic audio drivers. When compatibility issues arise, they are typically caused by Windows update conflicts, corrupted system files, or USB port power management settings rather than a missing proprietary driver. Step-by-Step Troubleshooting and Installation on Windows 10 Philips Spa5210 Driver Windows 10
Windows sometimes routes audio to your laptop's internal speakers instead of the newly connected USB soundbar. instructions for manually updating the driver in Device
instructions for manually updating the driver in Device Manager? Although Philips has discontinued the SPA5210
According to the user who discovered this method, the soundbar immediately began working after performing this final enable step. The downside is that you'll need to repeat these steps each time you want to use the SPA5210, but it serves as a reliable fallback when other methods fail.