I project my display on to a large 4K external monitor, and use the Surface dock. Couldn't figure out why all of a sudden my display was set to 4:3, instead of 16X9. Realized a new update was installed, and the Surface Pro needed to restart. I did that, but the display was still set wrong. Went in to the settings, and somehow the latest update changed my display resolution down from suggested, to something else. I had to set it manually to suggested, and all is well.