Black screen after waking from suspend on Ubuntu 20.04

I am very new to linux. On my laptop I have a multiboot with Windows 10 and Ubuntu 20.04 on the same disk.

The problem is when I suspend to RAM and then wake it up by pressing the power button, the disk starts running, however the screen remains black. I tried logging in blind (the screen was still black and I tried using the keyboard), opening terminal and typing reboot and that works.

Looking for solution, I found this thread. One of the solutions were to sudoedit /etc/default/grub and add nouveau.modeset=0 to the line that says GRUB_CMDLINE_LINUX. Apparently it's an nvidia driver bug. Except I have AMD CPU with Radeon graphics, so this isn't my case, right?

Another solution was installing xscreensaver, which I already had installed. I also checked the possibility of having the swap partition encrypted which also wasn't the case.

Is it some problem with AMD drivers? Can you please help me find a solution?

My hardware is HP Probook 455 G7 with AMD Ryzen 3 4300U, AMD Radeon Graphics and 16 GB RAM. I am running 64bit Ubuntu 20.04.1 LTS, GNOME 3.36.3 and kernel 5.4.0-47

Seems like an amdgpu issue, which is resolved in kernel 5.8. As the current kernel is 5.4, you should do:

sudo apt install linux-generic-hwe-20.04-edge

I found the answer here: Is there a kernel 5.8 ppa for ubuntu 20.04?

I stumbled across this post and have an Nvidia card. The sudo ubuntu-drivers autoinstall fixed the issue for me.

So for anyone with Nvidia cards, it seems that clicking on 'additional drivers' doesn't have what an autoinstall does.

Update: Yes the above fixed if one has Nivida and same blank screen after suspend, yet found issue remain if logged in, and suspend resumed as normal if I logged out first then suspend. Then resume normal. Strange.

For debugging I use to have separate home partition and swap partition and all this now since found do not need seaparate partitions. Anyway found another post suggested:

... sudo apt install gnome-screensaver ...

Now No more blank screen after suspend resume. So an easy fix:

... sudo ubuntu-drivers autoinstall && apt install gnome-screensaver ...

p.s. I think it is to do with 'no-more' separate swap and root partitions, and current Nvidia video drivers. not technical so just saying. Thank you all at ask Ubuntu, posting this for others. Happy puppy :-)