Trying to record using external audio interface

Go to System Preferences/Security & Privacy/Privacy and click on Microphone in the left sidebar. Then scroll to iMovie in the right hand pane and check the box next to iMovie. You will need first to click on the little lock icon at the bottom of the left sidebar, and sign in, in order to make changes. See if that helps. I know it works to enable the built in mic, but not sure if it also works for external interfaces.

-- Rich

Yeah, this is puzzling. It almost seems that your audio interface is not connecting correctly with your Big Sur and iMovie setup. Did you check its specs to see if it is compatible with Big Sur? There may be a website or forum for the AXE IO Solo where perhaps your issue can be addressed.

At this point the only thing I can think of is to redownload iMovie and see if that solves it. Drag your iMovie app from the Applications folder into the trash, but do not empty the trash. Then sign in to the app store and redownload/update iMovie from the display of your purchases. If the redownload is unsuccessful for some reason, drag your iMovie app out of the trash and place it back it in your Applications folder.

If a redownload doesn't work, then you might consider contacting Apple Support. The techs there have the capability of remotely accessing your computer, that we do not have here. Click on the Contact Support item in the upper right hand corner of this forum's screen and navigate to a place where you can input your phone number for iMovie issues.

-- Rich

Hmmmm. Your input source should be showing your external interface, not just "System Setting". Does it show it when you click on the v next to 'System Setting"?

Try creating a new project and see if the recording will work there.

Also, it may be that your external device is not compatible with your present iMovie app or operating system. Check the software information for the interface to confirm that it can be used with iMovie.

-- Rich

Try going to Applications/Utilities/Audio MIDI Setup app and confirm that your external mic is listed and selected in the sidebar.

-- Rich

Interesting. On my set up I notice that my Audio MIDI shows the Master slider engaged and displaying a 10dB value, whereas yours does not. Try sliding the Master slider handle to the right and see if that makes any difference.

-- Rich

If you have time, post back with what Apple Support came up with, as it might help others with this same problem.

-- Rich