I had the same problems with the event id 18.
Applied all the latest updates for the BIOS, chipset, Graphics card. No change.
Then I did a bios factory reset. Left everything on auto, I just applied the XMP Profile. PC has been stable since.
Ryzen 3600, Mainboard Gigabyte Aorus B550M Elite, Asrock Challenger 5600xt
Okay, I have pinned this forum for about 3 months now checking in on possible solutions.
I have a 5600xt GPU
Ryzen 5 3600
Tomahawk b450 max
My computer was fine for about a week and it has had all the crashes and errors you guys have had. Nothing would work for months and I have tried basically every solution. Two weeks ago I decided to open up my pc to take out my GPU and sell it to someone who actually had a working pc. While double-checking everything, I realized my CPU thermal paste was not very well done. (Never letting my friend help build a pc again lol). I re-did the paste myself and got a new, non-stock fan.
After turning it on and giving it one more try, I have had no problems. I have played VR perfectly fine, all other games with no errors. Here is what I recommend doing:
1. Check wires and hardware connection, and if you have not already, do not use your stock CPU fan if you have ryzen. It's not that good.
2. Turn your GPU fan up, I never let my temp go over 50 degrees
3. If you are an avid VR user and also use the Oculus rift S. First of all I am so sorry the index wasn't the first choice. Second, unplug it for a bit if you have any crashes, do not just restart and go back in that will make it worse.