: For devices appearing as "Borofone BR21 Stereo," you can download the verified driver package from DriverIdentifier .
Because the official site is difficult for international users to access, the files are widely mirrored by the open-source and hacking community on GitHub. jieli br21 driver link
: Many "Bluetooth dongles" using this chip actually function as external sound cards that transmit audio via Bluetooth, rather than acting as a standard Windows Bluetooth adapter. Troubleshooting Common Issues : For devices appearing as "Borofone BR21 Stereo,"
(and its sibling, the BR17) often acts as a rather than a generic Bluetooth adapter. jieli br21 driver link
To save yourself future headaches: