If there is no rotate option available for displays connected through a dock, check that DisplayLink software is installed.
If the DisplayLink Manager is installed do the rotation through that instead of using the System Preferences: Displays rotate option (which is not available). If this fails, check the DisplayLink software is fully up to date.
I usually write a blog post about once a week. The latest post can be viewed here: Stop the Tribalism: They really need to stop the tribalism. (posted 2024-06-26 at 19:56:52). I do podcasts too!. You can listen to my latest podcast, here: OJB's Podcast 2024-04-30 The Fall of Rome: I'm afraid that we really might be seeing the demise of the greatest era in history..