64gb ddr5 has been a huge problem on my board as well (extreme z690). I had 4 sticks equaling 64gbs couldn't run all four for nothing, without errors. I can run 32gbs xmp/,manual whatever no problem(even overclocked alil), but the minute I add 2 more sticks its a $%^% show. I even ran it at stock speeds, only lasted an hour or so before crashes. 64gb problems are inherent it seems to alder lake. I cant speak for all other manufacturers but I know plenty of Asus owners with similar 64gb issues. I ended up selling my other kit on ebay since I couldnt use it. When theres a definite compatible ddr5 64gig kit, ill try to pick it up. I just cant help but wonder people(workstations) who have large ram requirements using alder lake if they cant get 64gigs to run.
