Macbook Air won’t detect Ethernet from USB Hub.

Machine : MacBook Air M5

USB HUB : Ugreen Uno CM888 7-in-1

Issues : Mac air won't detect any ethernet coming from this USB hub, while I tried to use the same stuff like the ethernet cables and the USB hub into Mac Neo, it works fine. Anyone ever encountered this issue?

I also did Claude Diagnosis on my terminal, and here's what claude found:

MacBook Air (M-series, macOS 26.6.2 / build 25G83) won't link USB-C Ethernet — same hub works on every other machine

**Hardware:** UGREEN Uno CM888 6-in-1 USB-C hub with built-in Ethernet. The Ethernet chip is an **ASIX AX88179B** (USB VID 0x0B95 / PID 0x1790), sitting behind the hub's internal **Genesys Logic USB-3.1 hub** controller.

**Problem:** On this MacBook Air, the wired Ethernet never links. Interface `en5` appears, I entered my uni's static IP correctly (verified), but `ifconfig en5` shows `media: none / status: inactive` and 100% packet loss to the gateway. Forcing media (`sudo ifconfig en5 media 1000baseT` / `100baseTX`) still returns `(none)`.

**What works fine:**

– Same hub + same cable + same wall port on a friend's **Windows laptop** -> full gigabit, no issues.

– Same hub + same cable on **another Mac** -> works fine, links immediately.

– On this Mac, the hub's **other functions all work** — HDMI, USB-A data, SD card, phone charging/data. Only the Ethernet is dead.

**What macOS shows on the broken Mac:**

– `system_profiler` / `ioreg` fully enumerate both the Genesys hub ("USB Vendor Name = GenesysLogic") and the ASIX chip ("USB Vendor Name = AX88179B"), both `matched, active`. So it's authorized and talking — not an "Allow accessory to connect" block.

– Chip enumerates at **USB SuperSpeed (5 Gbps)**, on USB configuration 2 -> Apple's generic **CDC-NCM** driver (`com.apple.driver.usb.cdc.ncm`).

– Recurring kernel error on both USB-C ports, under both drivers:

`endpoint 0x81: status 0xe00002ed (transaction error): 0 bytes transferred`

followed periodically by the device detaching: `upstream hub is terminating` / `en5 does not exist`.

– Endpoint 0x81 is the interrupt-IN endpoint the adapter uses to report PHY link-state to the host — so macOS never sees "link up."

**What I've already tried / ruled out:**

– Full network-settings audit: no VPN, no proxy, no DNS override, no config profiles / MDM, ALF firewall off, not in any bridge, no third-party network kexts/filters/daemons, no Internet Sharing, no boot-args. `en5` is service #1 and enabled.

– Installed ASIX's own macOS driver (ASIX USB Device Installer v2.5.0, DriverKit DEXT). Approved the system extension, cold-booted. The DEXT bound the device and the chip initialized cleanly (`ax88179_hw_init end (0x0)`, `ax88179_NegotiateSpeedDuplex end (0x0)`) — **but still no link**, same endpoint 0x81 transaction errors. Same failure under Apple's NCM driver and ASIX's driver.

– Deleted `/Library/Preferences/SystemConfiguration/` plists (NetworkInterfaces.plist, preferences.plist, network.identification.plist) and rebooted so macOS rebuilds the network DB — no change.

– Tried both USB-C ports, powered vs unpowered hub, different port for power vs data.

**Working theory:** a USB-transport / xHCI incompatibility between this specific Mac's USB-3 controller and this AX88179B's SuperSpeed implementation on macOS 26 — the interrupt endpoint that carries link-state notifications fails at SuperSpeed. Windows and another Mac tolerate it; this one doesn't. There's no macOS knob to force the hub's built-in Ethernet down to USB 2.0.