Display Configuration Not Switching on External Monitor Coect

I have a Toshiba Satellite laptop ruing Ubuntu 16.04 LTS. I'm using an AMD graphics card with the open source drivers (about this computer displays "Graphics: Gallium 0.4..."). Back on 15.10, whenever I coected my exteal monitor, it would automatically switch the display configuration to use it the way I had configured.

However, after I upgraded to Ubuntu 16.04 via the in-place install, it no longer automatically switches. It will switch configurations as soon as I bring up the System Settings window, but not sooner. Similarly, once I discoect the monitor, I have to open System Settings again in order to force it to switch back to the single-monitor configuration.

It is worth mentioning that another Ubuntu 16.04 LTS Toshiba Satellite, ruing the exact same graphics driver, does not have this problem. What do I need to do in order to make my laptop switch automatically again?