Steam sometimes prevents system from going to sleep

[buu342]

Your system information

• Steam client version (build number or date): Wed, May 17 9:36 PM UTC -08:00. I installed Steam through the deb on Steam's website.
• Distribution (e.g. Ubuntu): Kubuntu 23.04, running Kernel 6.2 and mesa graphics driver. Hardware is: Ryzen 7 5800X, Radeon 6700XT, 16GB of RAM.
• Opted into Steam client beta?: [Yes/No] Yes and No (issue happens in both).
• Have you checked for system updates?: [Yes/No] Yes, I always install updates when they are provided to my system.

Please describe your issue in as much detail as possible:

I've been having this issue ever since I've had this desktop (so almost a year now). I've always run Kubuntu (Ubuntu using KDE Plasma as my DE) on it, starting originally with 22.04 LTS, and then I moved to 22.04 rolling release, and I've basically been keeping the system up to date up until 23.04. Same goes for the kernel, originally starting on 5.26 and I'm currently on 6.2.

When I try to suspend my system, it will fail to do so every now and then. Typically when suspending, the desktop fades to black, leaving only the mouse cursor visible, and then eventually the cursor disappears too and the system goes to sleep. But every now and then, the cursor will not disappear, and eventually the black will fade into my lock screen. I assumed this was a random Kubuntu bug for a while, but I one day got annoyed with the issue and decided to try to figure out why it was happening. I used journalctl -b, and the only information I could find was this:

https://gist.github.com/buu342/822bfa2e433281f288206cb25d893ef6

For reference, here is a successful suspend:

https://gist.github.com/buu342/8e8da5f40158da2ec309fe420dce9960

I doesn't seem to tell me anything interesting. I then tried killing different applications and suspending each time. The key was killing Steam. The past two months, whenever my system randomly decides to not sleep, I exit Steam (I have to wait until the Steam process is completely dead) and then suspend will work without flaw. I haven't been able to figure out why it happens specifically. Steam has managed to suspend without problems during updates or shader precaches, but will fail to suspend when it seems to be completely idle. It seems utterly random, which sucks because it makes harder for me to provide a minimal reproducible example.

Steps for reproducing this issue:

1. Try to suspend the system
2. It does not
3. Login and kill the Steam process
4. System suspends without issues