I don't understand what you mean by "different OS". Win 8.1 on both laptops.
Anyway, I did some more fiddling. I unplugged the HDMI cable from TV and laptop, switched ends and plugged the cable in to TV and laptop. Then I turned on the TV and set the input to HDMI 3. TV gave message "searching for a signal". Then I powered up the laptop. SUCCESS!
As much as I can remember, the power on sequence is the only thing I did differently. Switching cable ends may have done something, but since it worked on the 11s, it is not a "one way" cable and may have had nothing to do with the success.
And, I didn't have to do any selection of displays on the laptop, it just switched to the TV.
Thanks, Jim