TL;DR: I bought a Roland FP-90X piano partly because it had Bluetooth MIDI. Pairing it with my Windows 11 PC succeeded. Notes never made it to my DAW. Notes I sent from the PC never made it to the piano. Three completely different bugs were stacked on top of each other. I shipped a free, MIT-licensed open-source bridge (Avalonia, .NET 10) that handles all of them: github.com/mayerwin/Perfect-Bluetooth-MIDI-For-Windows . This post is the debugging story. The setup I have a Roland FP-90X (a digital piano with Bluetooth MIDI built in) and a Windows 11 PC. I wanted the obvious workflow: Pair the piano with the PC over Bluetooth. Open my DAW (or any Web MIDI app in Chrome). Pick the piano as a MIDI input/output. Play. Windows happily showed the piano as a Bluetooth device. Device Manager listed it. The Bluetooth icon was solid. Nothing red, nothing yellow. And yet the DAW saw nothing.…