Windows Core Audio (PKEY_AudioEndpoint_StableId): StableId changed after update of custom USB audio driver, what determines its stability?

PKEY_AudioEndpoint_StableId is generated by Windows, and its exact algorithm is not publicly documented. Its stability can depend on the audio driver, USB device/firmware information, USB descriptors, bus type, and endpoint/device identity.

So, even if the INF file and endpoint configuration are unchanged, updating the driver can cause the StableId to change.

There is no documented INF setting or driver API that lets a driver explicitly force the StableId to remain unchanged. The driver should preserve the underlying device/endpoint identity information, but Windows ultimately determines the StableId.

For your case: if 6.14 → 6.16 changes the StableId despite identical INF/configuration, compare the USB descriptors, PnP/device identity, and audio topology exposed by both driver versions. If those are identical, the change is likely due to Windows’ internal StableId generation/preservation behavior.