I upgraded my M4 Mac to macOS Tahoe and started getting constant Wi-Fi drops and ERR_NETWORK_CHANGED errors.
What I found:
awdl0 and llw0 consistently get the same MAC address• (should never happen)
Why do you believe that? Neither connect to any network architecture, nor do they communicate with the same endpoints. awdl is handoff/continuity and llw is for low latency connections to Apple servers.
A ghost ap1 interface is always present and • cannot be removed
I'm not sure what you mean by "ghost." It is the "access point" interface used when establishing a wifi hotspot (internet sharing). On Apple Silicon, it seems they enumerate all of the interfaces, used or not.
Multiple utun0–utun6 interfaces appear even with • no VPN installed
Yes, and…?
None of that is abnormal, as far as I can tell. Your Wi-Fi being unstable is abnormal. I only use Wi-Fi on my M2 MacBook Pro and I don't see any instability on that. My M4 Mini is connected via Ethernet, so I can't say if it has any Wi-Fi issues. WiFi is on for Handoff/Continuity/Universal Control and I don't see any issues there (but that is not a continuous connection).
• Wi-Fi disappears for a few seconds and then comes back
The issue • survives reboot, reinstall, Safe Mode and even a separate admin user
If it is awdl, you could disable all continuity and handoff features to see if that resolves it--at least you'd have a source to report to Apple. I don't remember seeing many Wi-Fi stability issues reported when Tahoe was released, but certainly could have missed them.
Long ago there were reports of Bluetooth interfering with WiFi (well before Apple Silicon), but I haven't heard anything like that recently. That's possibly another thing to turn off to test.
Apple AST diagnostics say hardware is OK
If you are having random disconnects, the wifi hardware could entirely be "OK" when tested, but still flakey; however, I doubt it is the problem, either.
downgrading isn’t always straightforward, especially on Apple Silicon systems.
I think it is pretty straightforward, but it has pitfalls that you must be ready to resolve.
- On Apple Silicon, erasing the drive completely could result in needing a DFU reset which would require another Mac running Tahoe. Erase All Content and Settings does not erase the System volume, only your Data, so that won't get you to a point where you can reinstall Sequoia.
- You need to create a bootable USB installer of Sequoia and boot from it before doing anything else. From there you can erase the drive then reinstall Sequoia using that USB installer.
- After reinstall, you can only migrate from a backup made under Sequoia, so if you have other data since then, you need to manually transfer it to another device before erasing and manually restore it after reinstalling the previous OS.
- Pretty much every major macOS upgrade now updates the firmware. If the firmware update caused the flakiness in your Wi-Fi, reverting to the previous OS may not resolve the problem. I don't know if Tahoe updated the firmware, and I don't know if you can revert the firmware, either.
I'm not sure I have ever completely erased an Apple Silicon Mac--I might have erased my M1 Mini, but can't remember for sure. I have used Erase All Content and Settings, but that is not the same. If your problem is somewhere in your Data volume (settings or third-party mods), Erase All Content and Settings might resolve the problem. Don't migrate anything to test it out. Create a different named user so you can migrate your user data, later.
