HDMI not detected on Ubuntu 18.04

Solution 1:

Try this:

sudo xrandr --output HDMI-1 --auto
sudo xrandr --addmode HDMI-1 1920x1080
sudo xrandr --output HDMI-1 --mode 1920x1080 --pos 0x0

Also you can use a GUI for xrandr:

sudo apt-get install arandr

Last try is to install latest nvidia drivers for the xserver:

sudo add-apt-repository ppa:graphics-drivers
sudo apt-get update
sudo apt-get install xserver-xorg-video-nvidia-410 nvidia-*

In your case upgrade the intel drivers:

sudo apt-get upgrade xserver-xorg-video-intel -y 

sudo reboot