I read that Thread a few times. So I can figure out that in this case, the thread of another Lenovo and bat-drains in sleep, the terminal commands "solved" the issue.
Well .... I really must say upfront I am not too keen on writing howto's in the blind and out of context or reverse of the things you are about to do. So please do not shoot me if things go wrong, I will NOT test this on my 100% good working Dell lol.
Here we go (please think 3 or more times before you just implement unreliable data from an unreliable source !!!! )
sudo apt update
sudo apt install sysfsutils
sudo echo "power/mem_sleep = deep" > /etc/sysfs.d/99-deep-sleep.conf
These 3 commands should be copied/ pasted in the terminal 1 by 1 .
For the last command I don't know if a reverse of the command is really possible, maybe some other experts can help a little here. But I 'think' it cannot be reversed. Anyhow ..... you can always do a fresh new installation and that brings me to a small tip: try a newer kernel from Ubuntu's mainline source.