
Check the ports on your Mac to find out whether you need an adapter. "Connect your display to power, then connect your display to your Mac. If your external display isn't detected or appears blurry on your Mac If the cable from your external display doesn't connect to the ports on your Mac, you can use a Thunderbolt 3 or USB-C adapter." "Disconnect the cable from your external display from your Mac, then reconnect it.

Based on what you stated, it seems like the second display is not working when connected to the iMac. Thank you for contacting Apple Support Communities. If the cable from your external display doesn't connect to the ports on your Mac, you can use a Thunderbolt 3 or USB-C adapter.", I'm half afraid, half furious, and finally very sad. When I read that the only proposition is "Disconnect the cable from your external display from your Mac, then reconnect it. It's such a shame ! Just when I started to thing that MacOs was not so bad.

The only solution from now seems to be to downgrade to Big Sur. So there is something looking like a dysfunction with the share screen capability. When I try to copy screens to it from the Mini, The second Screen of the mini start to work, displaying a copy of one the other screens (1st screen of Mini or screen of Air, depending of the display parameter I try). It was working fine with Big Sur and started to fail after being upgraded to Monterey.Īfter several hours of tests (first thinking that I forgot something myself), I'm fed up and I give up. I have the same problem here On a Mac mini M1.
