My MIDI controls have stopped working.

Uninstall and reinstall the MIDI Plugin in the Stream Deck store.

If the issue persists, click any button in the SD software and change the Layout and MIDI ports.

In the MIDI Out Ports Set to Mackie2Daw and in MIDI in Ports set to Daw2Mackie. DO it only in one button and it will set the rest.

If you still find a conflict, ensure the Stream Deck device is connected directly to the computer and not into a Hub. This could cause conflicts with other peripherals connected to the same hub and prevent the MIDI ports from appearing.