I recently installed Ubuntu 20.04, originally with MATE desktop. But due to an issue that that Xorg is gluttonously eating up my memory (see the linked Ubuntu bug for more detailed), I installed xfce desktop on top of the existing installation. Here are the Ubuntu packages I installed:
- xfce4
- xfce4-power-manager
- xfce4-screensaver
But here is the problem. In my desktop environment, from time to time I noted that the screensaver failed to engage (turn on) even after many HOURS I left the computer behind. One, this is a security concern, but the other, it is a power and hardware longevity concern. This failure happens both under XFCE and MATE desktop. I first tried to ask this on Ubuntu Forums to no avail, so now turning to askubuntu.
Can you help me drill down to the root of this problem? To be clear, I am now focusing on the issue I noted with xfce4-screensaver, not with mate-screensaver as per the originally posted question in the linked forum.
A few additional points I've discovered:
My current desktop usage: the open GUI programs are usually LibreOffice and Firefox. I don't play a video in Firefox when this problem occured.
A few days ago I discovered that that screensaver problem suddenly "disappeared" when I closed Firefox. That is odd. Seemingly Firefox was mucking with the screensaver inhibit for a reason I don't know. Problem is, I am unfamiliar with screensaver inhibit in today's Linux desktop, so I don't know where to hunt for problems. I had the screensaver running with debug output, so I can supply parts and pieces of it if it helps.
I suspect something with systemd or logind is at play here. Again, because of my unfamiliarity, this suspicion is unfounded right now.
The problem happens randomly, I still don't know what trigger the issue.
NOTE: Since this is a production machine with lots of "moving parts" and I rely heavily on it 7 days a week, please don't ask me to reinstall everything from scratch with xubuntu-desktop. I won't do it. That is the "Windows user" mentality (always reinstall, always reboot).
Would suggest you install Xubuntu 20.04 to get the best possible xfce experience. One that may not be conflicting with the Mate desktop settings. But if you don't wish to do that, you should likely install the xubuntu-desktop package to make sure its bringing in everything that it should if it were a Xubuntu installation.