i feel your pain i spent many hours over many days on my first rig..

what risers do you have? VER 0002 and flaky with vega so i binned them for VER 0003 and 0006

do you have a SSD or traditional HDD?

problems i see with the setup guide

in bios set all pcie slots to gen2, then in boot - enable csm and set all options to uefi

you will need to reinstall windows if it doesnt boot

when complete disable windows update then
shutdown
insert first vega first full size slot and install blockchain drivers
shutdown
install all other vega firstly into the next full size slot then any others
boot windows it should load desktop but then freezes for a minute while it detect and install the drivers for the first card.