Plugged in my Alfa Wi-Fi adaptor after installing 8812au and the light on the adaptor comes on when the system boots.
I have another WiFi adaptor by tp-link and in the Windows 11 that I dual boot with the light on the adaptor works.
In Manjaro although the adaptor works well the indicator light does not work.
This isn’t a problem but just out of curiosity I wonder why there is no light in Manjaro
More likely there’s some specific Windows hook in software to trigger it that wasn’t deemed important enough to replicate for Linux; or at least, not in all distributions. Often, software is built for Debian/Ubuntu with others being merely an afterthought.