for anyone who is having problems with this motherboard and network cards with the RTL8111/8168 chip on debian/proxmox, after hours of hair pulling, I finally have a solution. you don't need any special packages besides the pve-firmware for proxmox and firmware-realtek for debian, you just need to do 2 things:1. enable IOMMU on the motherboard configuration2. only on proxmox, enable IOMMU by editing the file /etc/default/grub and adding "amd_iommu=on" to the GRUB_CMDLINE_LINUX_DEFAULT variable. then execute update-grub to update the configuration and reboot the system.that's it, now your network card will work, just don't ask me why.