I know that this problem is not related to Fedora. However, I am sharing it here since I use this OS as my daily driver on both my personal and professional workstations. I am seeking the attention of any individual who uses Signal and/or Discord.
What I am seeing is that these two apps are somehow responsible for the prevention/inhibition of automatic sleep.
From the journal logs, this is what I found.
kwin_core: Failed to delay sleep: Sender is not authorized to send message
When I tried running this command, systemd-inhibit --list, I got the following output.
WHO UID USER PID COMM WHAT WHY MODEModemManager 0 root 1078 ModemManager sleep ModemManager needs to reset devices delayNetworkManager 0 root 1159 NetworkManager sleep NetworkManager needs to turn off networks delayUPower 0 root 984 upowerd sleep Pause device polling delayDiscord 1000 lonewolf99 1030624 Discord sleep Application cleanup before suspend delayPowerDevil 1000 lonewolf99 2268 org_kde_powerde handle-power-key:handle-suspend-key:handle-hibernate-key:handle-lid-switch KDE handles power events blockScreen Locker 1000 lonewolf99 1961 kwin_wayland sleep Ensuring that the screen gets locked before going to sleep delaysignal-desktop 1000 lonewolf99 2622 xdg-dbus-proxy sleep Application cleanup before suspend delay
7 inhibitors listed.
I can see that these two are trying to delay the automatic sleep. But I believe the prevention of sleep is somehow contributed to by these two apps.