Edit: In general without Apple, BT File Sharing has never interop'd. It's better to use a third-party app that uses BLE or a cloud or chat app with file sharing.
>In general without Apple, BT File Sharing has never interop'd.
I've used it with Windows, Symbian and Android at least, sending small files to each other without issues. The main problem is that it's just very slow.
Wi-Fi Direct (also used in 'AirDrop') however, doesn't interop. Windows and Android even both call their implementation 'Nearby Sharing' — but they're not compatible.
Edit: In general without Apple, BT File Sharing has never interop'd. It's better to use a third-party app that uses BLE or a cloud or chat app with file sharing.