Unraid 7.0.1 PCIe Splitter malfunctioning with Multi-HBA Card

[KuraudoLogan]

Current setting as NAS is as follows:

EPYC 7F32, ROME8D-2T, 8*64G 3200 RECC, ARC B580; running Unraid 7.0.1

UEFI, Above 4G Decoding, ResizeBAR Enabled; CSM Custom: Enabled UEFI for GPU, Enabled Legacy for HBA Cardz, but Disabled for any other M.2 Storage Cards

With PCIE channal splitter MOTHERBOARD in PCIE-7 (configured in BIOS to divide as x8/x8 and running at GEN3), connecting 2 SLAVEBOARDs with SlimSAS Cables and dedicated power through PSU.

Here's the thing, The 2nd SLAVEBOARD doesn't seem to react when I installed the 2nd 9305-24i(SAS3224) onto it, while the same model of SAS3224 works well on the 1st SLAVEBOARD. And when I switched the 2nd HBA onto 1st BOARD, while 1st HBA onto the 2nd BOARD; the 2nd HBA(1st SLAVEBOARD) works.

Next I tried to Put a HBA card into the Native PCIE-6 Slot, while leaving another HBA still in the "Working Well" 1st SLAVEBOARD. In this case, BOTH HBAs Function Correctly.

I'm onto checking if there's any physical problem with the 2nd SLAVEBOARD. Wonder If you guys can help with mentioning possible mis-configurations of my build. Thanks.

[KuraudoLogan]

Btw the last 13600T Minecraft Server Plan was carried out but it burnt down in a fire hazard with possible short-circuit of one of the "Physical Manual Tuning" Fan Controllers. So this buddy here is the 2nd plan of All-In-One NAS/PersonalServer Config