I suppose it's worth pointing out that this is definitely a repeated issue with Linux (and Proxmox) on the big-name #miniPC ecosystem.

get a mini PC that was originally a high-end model, chances are it has an Intel NIC which is absolute trash.

get a mini PC that was originally a lower-end model, chances are it has a Realtek NIC which is absolute trash.

get a USB NIC, chances are it has a Realtek chip and/or reverse-engineered driver which is absolute trash.