My favourite thing my Ubuntu machine does is that when you wake it from sleep, it shows you the desktop as it was when you put it to sleep for a fraction of a second, then flickers a few times while it puts up a lock screen, then shows two login dialogs stacked on top of each other, one larger than the other.
Thats probably because the lockscreen is just a fullscreen application under X11, Weyland actually understands the concept of a lockscreen and keeps things a tad more secure.
With KDE4 I often have to wait whilst the lockscreen is paged back out of swap.
Invariably I miss the fact that the disk-activity light is still lit, start typing my password and then become annoyed because it only caught the last few characters. So then I have to wait AGAIN whilst it proudly announces an authentication failure and punishes me with a further delay.
So your problem was a process going to swap (or not, Linux still has problems with disk i/o, especially going from hybernation, although bug #12309 is gone), rest are the consequences.
I've seen this behavior with the old 'gnome-screensaver' (which I think ubuntu hasn't used for quite a while), but with the current gnome-shell lock screen it behaves properly and doesn't black out the screen when I open my laptop.
At the risk of sounding like a fanboi: try Pop!_OS (I know, the spelling is ridiculous). It's essentially Ubuntu with a bunch of those things that make it feel janky ironed out. The biggest one for me is it does a great job of managing the discrete GPU on my laptop. I've been using it for a few weeks and couldn't be happier.
My understanding when looking back at those bugs, is that they were driver bugs where the driver lied about having committed to the back-buffer. GNOME, at least, tries to blank things and submit the right commands to ensure it's cleared before releasing the suspend lock.
But if the GPU driver is broken about command committal, then there is only so much you can do short of fixing those .
