The last selected audio interface is not available. The previously selected interface "iMac" will be used instead for this session.

I use a Scarlett 2i2 USB audio interface and it this is selected in settings< device< audio. Recently after a few minutes that the project is opened and Scarlett is working normally in the Logic X, I get the message "The last selected audio interface is not available. The previously selected interface "iMac or Zoom" will be used instead for this session" and then Scarlet i2i2 USB is not visible anymore in Settings<device<audio, even though it is connected. I tried to connect-reconnect-turn my computer and Logic X on and off, conect and disconnect Scarlet 2i2. On the next day, I open Logic X, it is working again, but only for some minutes, I get the same message. I always check if the Scarlet is connected on my iMac and it is on the Settings of my iMac and in the Logic X but only for some minutes. Once it is selected, it should continue until I close it. So, I don't know what to to anymore!