This is what I saw in my test environment. I've sent my logs to devs.
I also tried on WS9. This issue still exists. However, since there was only a multiple monitor button ( no dropdown menu ), I can switch back to the 3-monitor-topology by clicking the button. 
Would you mind to send your logs to yingjisun@vmware.com so that I can help to forward to the developer ?
Thanks.