I am able to suspend my desktop just fine if I select "leave -> suspend" from the KDE menu. However, I also have "suspend session after 60 minutes" configured in the energy saving tab of the system settings. This used to work, but no longer does. I am not sure why it stopped working. I've tried rebooting and making sure any applications that might be keeping it from suspending are closed. No luck. How can I debug this issue?
It seems that bluetooth was keeping my computer from auto-suspending after 60 minutes of idle activity. After turning bluetooth off, my computer started auto-suspending again. I'm not sure why this is the case, but just an FYI for anyone else who may have the similar issue. If someone knows why this is the case and posts a good explanation, I will be happy to accept your answer.