There, I Fixed It: Lenovo X1 Carbon 6th Gen Ethernet Port + Thunderbolt Port fit : r/Lenovo
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2.5GbE USB A Ethernet Adapter NBASE-T - USB and Thunderbolt Network Adapters | StarTech.com Europe
StarTech.com 2.5GbE USB A to Ethernet Adapter, NBASE-T NIC, USB 3.0 Type A 2.5 GbE /1 GbE Multi Speed Gigabit Network, USB 3.1 Laptop to RJ45/LAN, Lenovo X1 Carbon, HP EliteBook/ ZBook -