Comment # 5 on bug 985741 from Richard Brown

Confirmed

This only happens when the battery is absolutely critical

GNOME appears to be attempting a hybrid sleep, but something wakes it up,
meaning it dies a terrible death when the battery runs out

Journal from an impacted machine is attached

When the battery life is not critical, it seems to behave properly. eg.
systemctl hybrid-sleep works fine when done manually, which means I don't think
we can easily blame systemd or the power management guys for this one :-/