Last month there were some motherboard makers that enabled PCI Express 4.0 support on 400-series motherboards. This was against the wishes of AMD, who wants to keep PCI Express 4.0 exclusively for 500-series chipsets to ensure "everything just works" because not every 400-series motherboard can support it.
AMD's new AGESA 22.214.171.124ABB microcode update contains measures to prevent PCI Express 4.0 from being activated on older chipsets. German tech site ComputerBase noticed both Gigabyte and ASRock have already rolled out BIOS updates that contain this microcode.
AGESA 126.96.36.199ABB also contains various fixes, including an update that should get Destiny 2 running again.