Problems with extended display on 2022 24" iMac
Have been unable to get my old 27"iMac (2011, Big Sur 11.6.7) to act as extended monitor on my new 24" iMac (Monterrey 12.5). Was told by Apple support that the new Macs using the M1 chip no longer will work using older iMac's as extended displays. Here is the article they referenced.
Use your iMac as a display with target display mode - Apple Support