Upgrade in legacy mode on the testpool with older IBM x3650 M4 Servers from XCP-ng 7.6 to 8.0 RC runs perfect
All networks, SRs and VMs up und running

Also a fresh installed XCP-ng 8.0 RC in UEFI mode on a Lenovo ThinkSystem SR650 with latest BIOS updates an Mellanox X5 Network Adapters works perfekt out of the box.

Nice work!!!