To be clear, it's only older motherboards for 8th and 9th Gen Intel CPUs that are affected by the issue.

ASUS is preparing new AM5 BIOS updates with optimized low-latency support for selected CXMT-based DDR5 memory. Beta AGESA 1.3.0.1d builds are already available.

Seems like they need BIOS flashback, although even that isn’t foolproof (ASUS killed my x670 board because they don’t allow rollbacks and their new bios was incompatible with my RAM). I also wonder ...