Lubuntu 20.04 hibernation

I have a swap partition, with its UUID specified in the GRUB_CMDLINE_LINUX_DEFAULT. If I type
sudo systemctl hibernate
then the system hibernates (and subsequently restarts) as I’d expect.

But from the desktop clicking Menu-Leave-Hibernate doesn’t appear to have any effect.

Any ideas?

I am new to Linux and I have installed Lubuntu a couple of months ago. I was wondering if it would be fixed by now with an update or something but so far I am in the same situation.