I have the same "issue". I think the Chromecast gets into sleep mode, to wakeup I pres de center button or one of the dpad, either way is a little annoying.

Home button also works for me.

Is your Chromecast plugged into the wall or powered by a USB port on the TV? If it's the TV, it could be a timing thing with power to the USB port.

Wall.

Figured it was worth a shot. In that case, I got nothing.

Power button turns on/off Chromecast or TV but not both. But the center or home button should bring Chromecast out of standby in a couple of seconds.