I've done a fresh install on my Lenovo Thinkpad Yoga S1 with Ubuntu 17.10. The machine won't go sleep. Actually, it seems it does try to put the system into the sleep mode then instantly wakes up showing the login screen. Both menu option (Pause) and closing lid cause the same, invalid behaviour. I've already configured via Gnome Tweak to fall asleep on lid close but it does not change behaviour.
Looking forward to any help. Is there any method to investigate, what causes immediate wake-up?