Linux Mint monitor not turning off and going to sleep

I’ve recently noticed that my desktop monitor is not turning off like it used to after 30 minutes of inactivity. It was working perfectly on Linux Mint 21 but after upgrading to LM 22, the monitor stays on, running the screen saver. Today, I noticed the screen turn off then come back on again after about 30-40 seconds, right around the 30-minute idle mark when it was supposed to be turning off.

It seems to be an upstream issue, inherited from Ubuntu.

The solution I found was here. After setting my monitor’s Input Source auto-select setting to “off”, the problem disappeared immediately.