Mac unable to set rotations of multiple monitors
I've solved this problem by making a safe mode reboot.
You need to shut down your MacbookPro, hold command + R. After you get into the safe mode successfully, restart it again.
This time you get into your Mac with a normal mode, and the dual rotation of monitors is working.
A rough assumption is that a safe mode reboot may cleared some cache of the system?
Hope my solution can be helpful to you.