Pi 4 HDMI1 not displaying

A few customers have noted that the HDMI1 output on their Raspberry Pi 4’s have been a bit uncooperative, specifically after performing certain updates. This has ranged from not working at all, to not working on boot, to not working unless the monitor/TV used is powered on and not in standby mode.

We have found what seems to solve the issue in all of these cases. To remedy this, you simply need to add the line of code below to the config.txt file found in /boot on the Pi 4: