I have upgraded my router to 4.4.6
The upgrade was successful, but when the router came back up the network ssid that was configured for 5Ghz network disappeared.
It is still enabled according to settings in UI, not set to hidden, but not available for devices to connect.
Export the system log.
Is the power plug the original one? All the client device can not see the wifi?
If that’s true, contact customer service please.