MediaTek Wi-Fi 6 MT7921 Wireless LAN Card disappear no wifi in Task Manager error code 45 in Device Manager, wifi driver are updated to last version my operating system is WINDOWS 11 AWUS1900 Wifi Adapter work with no issues !!!
Press and hold the power button for 60 seconds (min). It will reset the hardware detection and will most likely fix the Wi-Fi.
I don't know what make the MediaTek Wi-Fi 6 MT7921 show error 45 in DEVICE MANAGER but right click and scan for hardware changes fix the problem for a while and wifi disappear again and again it is driver issues for sure no fix I did everything changed registry PLATFORMAOACOVERRIDE to 0 all power option and plans showing up DISABLED Allow computer to turn off this device to save power Wireless Adapter Settings already at Maximum Performance
then if you have win11 try updating both the Wi-Fi adapter (3.3.760 WHQL) and Bluetooth.
many users have solved this problem
pressing the power button for one minute
or by installing the drivers
MediaTek Wi-Fi 6 MT7921 Wireless LAN 3.3.760 WHQL drivers
Bluetooth MediaTek 1.930.3.287 WHQL
(this operation is however different from updating the drivers).
Some have solved all problems by changing the wireless network card, (which is also faster).
Other than that I don't know what else to say, maybe you could contact Asus support.