P2715Q, DP/mDP handshake problems?

Last night I shut off just the monitor not my entire system (XPS8700). Came back half hour later, hit the power button and the mini display port cable wasn't recognized. I finally had to pull the power cord to get it back. In the process I lost the USB hub. I was finally able to get it back by powering off the monitor a few times via the power button. Has this happened to anyone else? Was a very, very frustrating hour or two before I was finally able to get the monitor up and running. I have an XPS8700 with the i7 4790, 32GB ram, a 500GB SSD boot drive, a 1TB data drive, and an AMD R7 260X video card. Power management is set to high performance.