No longer able to use Target Display after Monterey update.
After the Monterey update, the Target Display feature is no longer an option. Pressing CMD+F2 no longer works as it did in previous versions.
iMac Pro
After the Monterey update, the Target Display feature is no longer an option. Pressing CMD+F2 no longer works as it did in previous versions.
iMac Pro
That's correct. TDM has been deprecated by Apple since 2014. No macOS newer than Catalina has the feature.
And no new Mac since 2019 can take advantage of it, either.
That's correct. TDM has been deprecated by Apple since 2014. No macOS newer than Catalina has the feature.
And no new Mac since 2019 can take advantage of it, either.
If you updated to Monterey from Catalina that is correct. Neither Big Sur (11.x) nor Monterey (12.x) support Target Display. If you read the support document provided in the link at the top of this page you would know that. Only macOS Catalina supports Target Display.
No longer able to use Target Display after Monterey update.