What OS? On macOS especially, it helps to plug in the headphones first. Or, go to Edit / Preferences / I/O after changing audio devices to tell MuseScore to use the new device. or toggle the MIDI button on the toolbar off then back on.
If you need further assistance, please ask on the Supprot forum and include more system information, then someone familiar with that type of system may be able to help further.
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What OS? On macOS especially, it helps to plug in the headphones first. Or, go to Edit / Preferences / I/O after changing audio devices to tell MuseScore to use the new device. or toggle the MIDI button on the toolbar off then back on.
If you need further assistance, please ask on the Supprot forum and include more system information, then someone familiar with that type of system may be able to help further.