For me, the most reproducible means of triggering errors due to PBO/CO (me using settings that were too aggressive) were triggered by light workloads as described here: https://wiki.archlinux.org/title/Stress_testing#Low_load_example
The patching of OpenWRT test is what I used.
You can put Arch on a separate partition or HDD/SDD if you want. Once you get it installed, see: https://wiki.archlinux.org/title/Stress_testing#Discovering_Errors
Windows may have a means of showing this but I do not use it.
False alarm. Ended up restarting, just took a little longer. The new ram kit (3000mhz off the MOBO's qvl) didn't help - restarted almost immediately. Tried the above (forced to 2133 and slightly higher voltage) and made it a little longer, but not much. The best results thus far have been the above (original 3600mhz ram manually set to 2133. Basically when I am using ERP for SME accounting software basically this is happening most. In theory, I'm not fixing either - I've got everything set to auto/default at the moment. I can try manually overriding either or both if you thought it would be helpful, but I haven't gone down that road yet (except for briefly with the ram).
Don't want to celebrate early as PC has its stable moments.
But came across one post about VDDP / VDDG CCD /VDDG IOD voltage settings.
Increased VDDG IOD voltage from 0.95v to 1.05v . And for 1st time I did play Modern Warfare , Black Desert Online and managed to render video for work . And no audio hiccups or restarts so far. Will test for a week before celebrating success .
If issue will appear again then will do Linux road of troubleshooting .
If anyone in future reading this post to find solution Did add snap with part of the info ( cant take credit for )
Also much appreciated everyone who invested time to help out.