Happened to me a few times too.
Using the Software installer, uninstall (only) the wireless drivers and re-install them again.
Samething happened to me today, try everything include ur way, all firmwares and related softwares are latest updated, nothings worked. However, the wireless signal reception and speed now are indeed more stable and faster.
The Fn-F5 still works for the bluetooth though, guess I have to use the hard-switch in front or right click to enable/disable to wireless adapter then