ASRock Z790 PG Sonic Memory Issue

Hi, i bought the ASRock Z790 PG Sonic at 2024-05-18 and stumble into the same issue. I have bought a 64 GB Kit consisting of 2x32GB from Corsair. It is Corsair DIMM 64 GB DDR5-4800 (2x 32 GB) Dual-Kit (CMK64GX5M2A4800C40). In the recommended combination A2-B2 it does not work. The A1 and A2 slot do not work in any combination.

I tried every combination.

A1     A2     B1     B2     works?     combi
X     o     o     o     No     A1
o     X     o     o     No     A2
o     o     X     o     No     B1
o     o     o     X     Yes     B2
X     X     o     o     No     A1-A2
X     o     X     o     No     A1-B1
X     o     o     X     No     A1-B2
o     X     X     o     No     A2-B1
o     X     o     X     No     A2-B2
o     o     X     X     Yes     B1-B2

The modules are sold as DDR5-4800. In the BIOS they show up with 3600.
It is difficult to determine are Corsair not supported or the mainboard or the ram are defect.
At this link https://pg.asrock.com/mb/Intel/Z790%20PG%20Sonic/Specification.asp#MemoryRPL the Corsair modules are not mentioned. May this is the cause?

JCLentine wrote: Two-ish months later. ASRock replaced the motherboard, Intel replaced the CPU and Corsair replaced the memory with a matching kit. The only change is that 2 memory sticks work in the B_1 and B_2 slot. The manual says it should be B_2 and A_2, yet that configuration does not work. It's very hard to judge if I'm doing something wrong, there is no documentation about the BIOS (or UEFI) This is ridiculous.

Two-ish months later. ASRock replaced the motherboard, Intel replaced the CPU and Corsair replaced the memory with a matching kit.

The only change is that 2 memory sticks work in the B_1 and B_2 slot. The manual says it should be B_2 and A_2, yet that configuration does not work.

It's very hard to judge if I'm doing something wrong, there is no documentation about the BIOS (or UEFI)

This is ridiculous.

It is. Even limited to a matching pair for a total of 32gb, it won't boot.

Anyway I've never seen a package of 4 together, it's always 2s.

I'm having the same issue with the memory, it?™s all over the place and I'm currently running at 3600MHz trying to get 6000MHz XMP setting or 5400MHz with four sticks of Kingston 8GB 6000MHz modules

I did find that one of the four sticks was PC-4800 and the others were PC-5600 but that should have just slowed the others down to 4800 instead of not booting at all. So even in a single package they weren't identical.

I haven't seen any memory offered as such anywhere, I've literally only seen memory sold in 2's. If I could have bought 4 in 1, I would have.

Also how am I supposed to test them with a freeware program when I cannot boot the computer to install an OS yet?