SysEx hangs MIDI stack, but not App using this code variation.

[Noemata]

As a follow up to my previous issue, this code variation might provoke some insight as it allows the App to keep running, the Manufacturer ID is received by the message handler, however the midi input is frozen for the associated device for any further calls:

                midiInputDevice.MessageReceived -= OnMessageReceived;
                midiInputDevice.MessageReceived += OnMessageReceived;

                // Get Vendor Id for port.
                var data = new byte[] { 0xF0, 0x7E, 0x10, 0x06, 0x01, 0xF7 };

                var backgroundThread = new BackgroundWorker();
                backgroundThread.DoWork += (_, __) =>
                {
                    midiOutputDevice.SendMessage(new MidiSystemExclusiveMessage(data.AsBuffer()));
                };
                backgroundThread.RunWorkerCompleted += (_, __) =>
                {
                };
                backgroundThread.RunWorkerAsync();

Sending a SysEx should never clog up IO! The code above suggests there is a bug in the UWP MIDI stack, since there is no issue sending SysEx messages under Win 10 Win32, and only the device associated with the SysEx call is hung with this variation of the code.

[Noemata]

And yet another variation. I'm guessing that the call here is the lower level call used by MidiSystemClusiveMessage():

                midiInputDevice.MessageReceived -= OnMessageReceived;
                midiInputDevice.MessageReceived += OnMessageReceived;

                // Get Vendor Id for port.
                var data = new byte[] { 0xF0, 0x7E, 0x10, 0x06, 0x01, 0xF7 };

                IBuffer buffer = data.AsBuffer();

                midiOutputDevice.SendBuffer(buffer);

Note: you'll need to try this with any of these: JU-06, JP-08, JX-03, TR-09, TR-8, System-1, System-1m, System-8, MX-1, etc.

The OnMessageReceived does receive the Manufacturer ID event and then the GUI hangs. If a clock is running on the device, events will continue to fire in OnMessageReceived even though the GUI is hung.