My MB BIOS was and is up to date.Not meant as a lesson in sucking eggs!
It might be worth your while to update the motherboard BIOS when upgrading RAM, as a newer bios might recognize the new RAM and be better able to work with it.
Again this has NOTHING to do with my system but my O.S early release and fresh install, there is NO update in this, it has to be installed before being updated, not worth the effort considering the trouble, much better doing a fresh install of Win 11 Pro 64 which had no trouble with the same system and BIOS.
For your info, I built my PCs since Pentium III and I know a thing or two about making sure those things doesn't occur, then the RAM was NOT "New" it was simply a 16GB/stick version of the previous, same die, same number of ranks, same latency and it worked with two sticks, meaning it was not the RAM but its capacity limit which prevented the O.S to boot after installation.
Not everything you read in Wikipedia or even Microsoft is applicable in real life.