Recently, I upgrade to macOS Big Sur (11.0 Beta (20A4300b)).
After upgrade, my tp-link usb wifi adapter(Archer T2U Plus model) no longer works.
I had tried to reinstall the driver, and even other driver from gitHub.
I also tried doing smc reset, nvram reset. Nevertheless, after restarting, my extended wifi adapter still can't work.
There is no issue regarding the wifi adapter itself. I am able to successfully connect adapter with my other laptop. Either type-c port directly or with a usb to type-c converter inbetween, both ports can recognize the adapter correctly. The adapter would start to blink after plug-in in 2 seconds, yet the adapter won't be able to blink at all for the Big Sur.
What can I do to make Big Sur work with this wifi adapter?
P.S. This is my working laptop, I had to bought this adapter after work from home period since its internal wifi is terrible. Even after the upgrade, the interal wifi still suffer network inconsistent issue heavly. Therefore I had to rely on the external wifi adapter to get decent network. While I upgraded the system, I didn't backup the system, so I can't time machine it back. And also wipe out the system would not be a good approach for me, especially still in lock down period.
Best Answer
Some types of kernel extensions – including USB Networking – are deprecated in macOS 11.
These kernel extensions have to be rewritten by the vendor using DriverKit to be compatible with Big Sur. See https://developer.apple.com/support/kernel-extensions (USB networking).
While macOS 11 is in development, you can enable the loading of deprecated KEXTs by disabling SIP. See https://developer.apple.com/documentation/macos-release-notes/macos-big-sur-11-beta-release-notes (Deprecations).