Games prevent the system from entering sleep mode

Games prevent the system from entering sleep mode. All I've managed to do with the system so far is create a systemctl service that temporarily enables WoL via ethtool on PC startup. That's all, no further interaction with the system. Log: https://paste.centos.org/view/0073fa7d The graph shows the PC performance after 20 minutes of AFK time. The system is configured to enter sleep mode after 20 minutes of inactivity.