Upgraded from 18.04 to 18.10, now suspend doesn't work anymore

I upgraded from 18.04 to 18.10 using the standard procedure, and now whenever I suspend my laptop it actually shuts down.

I notice this only after I press the button to "un-suspend", because I see the whole boot process happening from the start.

Any idea on how I could fix this?

Solution 1:

I seem to have fixed this by following the instructions in this answer, even though they are from 7 years ago...

Edit the following line in the /etc/default/grub file:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

Change it to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_sleep=nonvs"

Save the file, then run:

sudo update-grub

and reboot.

I wonder why I didn't need to do this with 18.04 and it became necessary only since 18.10.