Hi Christos Bakrozis,
Welcome to Microsoft Community.
"Lately it is not working properly."
"I currently have Windows 11 Pro, version 23H2, build 22631.2715. I didn't have any problems on Windows 10 and even on Windows 11 until lately."
These are relatively important pieces of information.
Compatibility conflicts are a common trigger for such phenomena.
If you have not previously experienced problems with Super DAC not working, try restoring the device to an earlier state, for example by uninstalling updates or returning to a previous version of Windows.
How to uninstall a Windows update - Microsoft Support
Recovery options in Windows - Microsoft Support
The problem is not unilaterally affected by the functionality of Windows; other drivers or software are also possible factors associated with this phenomenon.
- This link provides drivers for Super DAC products, and we note that M-Audio Super DAC products do not appear to have released drivers for Windows 11. M-Audio
Disclaimer: Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites or any support related to technology. - Try installing older versions of drivers for other products (for example, but not limited to, motherboards, chipsets) in addition to the drivers for the Super DAC product.
If I misunderstand your situation, feel free to correct me and share the information.
Best Regards,
Kyo - MSFT | Microsoft Community Technical Support