Envy x360 laptop external display no longer decected

[PookahSF]

I have an Envy x360 Convertable (15-aq294c1) on Windows 10 64-bit. I use an AOC monitor as an extended display connecting to the HDMI port. Today, I started my computer and my extended screen wasn't working. 

I've checked that the monitor works. I tried a different HDMI cable that works. I tried connecting the laptop to another monitor with the same HDMI cable and with another cable. Nothing worked. 

I did try going to PC settings > System > Display > Multiple Devices and hit detect and a second monitor wasn't detected. see screen shot. 

I also tried detecting the device using Intel Graphic Settings by right-clicking on the desktop. Nothing. 

It's not the cables. It's not the monitor. It must be driver-related. Or the physical hardware of the HDMI port no longer works. 

I'm not sure what to do next. Thank you for your help. 

[PookahSF]

Well, after all that, I restarted the computer (which I had done several times before), and this time it worked. I'm not sure exactly why. I tried so many different combinations of restarting the computer with the cord plugged in and not, so one of them must have worked. 

I guess this is closed.