I have the similar issue, but the different error log.
My CPU Ryzen 3600 crashed very rarely and forced my PC to reboot immediately, when watching/opening YouTube in the browser Vivaldi with hardware acceleration.
Jan 05 16:39:33 zesko kernel: mce: [Hardware Error]: CPU 11: Machine Check: 0 Bank 5: bea0000000000108
Jan 05 16:39:33 zesko kernel: mce: [Hardware Error]: TSC 0 ADDR 1ffff9cf29d14 MISC d012000100000000 SYND 4d000000 IPID 500b000000000
Jan 05 16:39:33 zesko kernel: mce: [Hardware Error]: PROCESSOR 2:870f10 TIME 1641400770 SOCKET 0 APIC d microcode 8701021
Jan 05 16:41:17 zesko kernel: [drm:amdgpu_job_timedout [amdgpu]] *ERROR* ring vcn_dec timeout, signaled seq=6293, emitted seq=6294
Jan 05 16:41:17 zesko kernel: [drm:amdgpu_job_timedout [amdgpu]] *ERROR* Process information: process vivaldi-bin pid 2084 thread vivaldi-bi:cs0 pid 2114
This happened after the stable update of Linux kernel 5.15.12 and mesa.
My guess is GPU RX 5700 triggered the CPU to reboot the system.
I tried to turn off PBO in BIOS setting of the motherboard ASUS prime B450, so far it does not crash yet. I will wait and see.
Before the stable Manjaro update, the error looks different without MCE error, but use the same behavior (It crashed when watching YouTube)
Okt 17 20:22:31 zesko kernel: [drm:amdgpu_job_timedout [amdgpu]] *ERROR* ring vcn_dec timeout, signaled seq=2315893, emitted seq=2315895
Okt 17 20:22:31 zesko kernel: [drm:amdgpu_job_timedout [amdgpu]] *ERROR* Process information: process vivaldi-bin pid 45233 thread vivaldi-bi:cs0 pid 45253
Okt 17 20:22:40 zesko kernel: [drm:amdgpu_cs_ioctl [amdgpu]] *ERROR* Failed to initialize parser -125!
Okt 17 20:22:40 zesko kernel: [drm:amdgpu_cs_ioctl [amdgpu]] *ERROR* Failed to initialize parser -125!
Okt 17 20:22:40 zesko kernel: [drm:amdgpu_cs_ioctl [amdgpu]] *ERROR* Failed to initialize parser -125!
It looks like your issue: DE froze with graphic glitches... lots of kernel, drm, and amdgpu entries in journal
I read a bit other forums, that someone has experienced that MSI motherboards have more problems than ASUS motherboard.