OK - have done these - as always here is my grub (again, just to remove the possibility of my making an error):
GRUB_DEFAULT=saved GRUB_TIMEOUT=5 GRUB_TIMEOUT_STYLE=menu GRUB_DISTRIBUTOR="Manjaro" GRUB_CMDLINE_LINUX_DEFAULT="quiet udev.log_priority=3 pcie_aspm=off radeon.runpm=0 radeon.modeset=1 radeon.drm=1" GRUB_CMDLINE_LINUX=""
I have noticed/wondered if some of this is related to how hot this system gets… fans are cycling on/off pretty regularly. I installed a temp monitor and will watch that and see if I see if freezes happen when the system reaches a certain temp. I’m also going to do a physical check for my fans - make sure they are physically working… and not clogged or broken.
I found this thread - any value into looking into it: FanControl
There was another thread that seemed similar to my issue - where there is a swap issue that causes a similar freeze? Is that worth pursuing? Freezing