On two of my Windows PC's, sometimes the computer won't even switch to HDMI regardless of how much I press the input button. Even after running a clean boot on both devices and seeing if any driver updated, I find myself stuck. The internet wasn't of much help either.

For reference, I have a 23" HP Envy and a custom built PC. It's the first time I (or my peers) have ever seen such an issue, so I thought I'd try looking on here for help.

Did you disable HDCP on your monitor?

Have you eliminated the monitor being faulty? Can you verify that it can still switch inputs using other devices?

It can't anymore. It was able to for a few minutes, but stopped. It's the strangest issue I have ever encountered. My friend (who enjoys fixing PC's as a side hobby) isn't so sure as to what's happening anymore. Disappointed to see the computer have a faulty HDMI, but I can't complain.