This back and forth in this thread about nuisances like that is one of the reasons I am definitely sticking up to Intel integrated GPU when running Linux. It's 2020 and stuff like that should be much smoother :-(.
Note that in my comment above i was referring to the Windows AMD driver. I haven't used Linux much with this machine (though when i did it had a 50/50 chance to completely hang the system, but i think this was an issue with the kernel and the then-new Zen APUs that was quickly fixed).
I have Lexa PRO in my workstation (Fedora) - Suspend/Resume works so far.
I have an issue though where switching off the monitor for a few days might make the AMD card disabling the outputs and not recognizing the monitor afterwards (I think it is related to the order in which I try to "wake" the monitor) - which I cannot recover from without rebooting the machine.
But this is with a machine never going into suspend or any sleep state - and I can't say if this would be the same with the NVIDIA card. I do not use the NVIDIA card for video output because the proprietary driver would regularly stop showing my desktop - or suddenly any output at all after reboot.
The integrated Intel GPU on my laptop is mostly without issues whatsoever.
On laptops I would still recommend Intel GPUs anyway for power consumption reasons - although AMD APUs are quite interesting and I don't have recent knowledge about how well they compare. The CPU and its ability to lower power consumption under sleep is also relevant there, and this was way better under Intel so far. Unless you need the increase in performance an AMD GPU/APU would offer...
Now when you turn the laptop (with Radeon gfx) on, it requires me to turn the monitor off and on before It is recognised.