Thanks for following up on this.
Unfortunately you can remove the faulty GPU from the list.
I had this issue starting a few month ago with an RTX 3070 that had always been working fine, and the issue remained after changing it for a brand new 5070Ti.
So the issue isn't there.
RAM is brand new Corsair as well. EXPO profile enabled but that's it.
Just ran a windows memory diagnostic. No issue found.
I've just ran an SFC /Scannow and a FragmentDISM /Online /Cleanup-Image /RestoreHealth as well.
Both finished without error.
That leaves Motherboard and Power supply. Harder to check I guess since nothing seems off besides thoses errors in the reliability manager.
Power supply is a Corsair RM850x (2024). So Brand new and high quality. I'm guessing unlikely to be faulty ?
Motherboard is brand new too and with good reviews.
I've updated the BIOS but errors are still here.