At least on the Rampage V Extreme you can try to play with the BIOS parameters that I shared in your other post "Rampage V some PCI-E slots not working"
MB: Asus Rampage V Extreme (WC loop1 rad 120x3) Bios 4101
CPU: Core i7-6950X (WC loop2 rad 120x9)
MEM: G.Skill Flare X 32GB (4x8GB) DDR4 3200MHz@CAS14/CR1
GPU: ZOTAC Trinity RTX 3090 Watercooled [double side] {PCIE_X16/X8_3 slot} (WC loop3 rad 120x9 + 140x9)
SSD: Corsair MP600 PRO XT 2To SSD M.2 NVMe w/ heatsink
HDD: 4 x 10TB Seagate IronWolf RAID 0 (WC loop1)
PSU: EVGA NEX 1500 1650W + Seasonic Fanless TX-700W
Main Screen: ASUS ROG Swift PG43UQ 4K 144Hz G-Sync/FreeSync HDR