Ubuntu does not wake after suspend but restarts

Question

I really love Linux and I'm trying to make the switch to Linux-only, however there is one problem that's driving me nuts. If I try to wake my PC after suspending it, 9/10 times it will just restart. This always happens when the computer is sleeping for more than 2 hours. I tried a ton of stuff I found on the internet (increasing swap file size, setting grub settings, doing stuff with gnome), to no avail. The hardware supports suspend according to pm-suspend check output. I've typed in so many random commands I kinda lost track of what I'm doing, so if someone could help, much appreciated!

Ubuntu is installed as dual boot with windows on a separate 500GB ssd drive. PC specs:

• Ryzen 1600
• 32 GB ram
• Radeon RX580
• Ubuntu version 20.04.2 LTS
• Kernel version: 5.8.0-50

Edit: forgot to mention my swap partition (according to free) is 39 GB.

Answer 1

I seem to have figured it out on my own. After browsing trough tons of bug reports, I found out it is probably caused by a crashing XORG-server. It does not restart the pc, it just logs out. The bug fix posted in this bug report solved it: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1760450

Fix that solved it for me:

Change the line in /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="quiet"

to

GRUB_CMDLINE_LINUX_DEFAULT="quiet scsi_mod.scan=sync"

and then re-run update-grub.

I left my pc suspended over the night and it didn't close all my programs in the morning, so it seems to be fixed.