HexFlash Bug turning grey and not working

I recently queued solo/duo game and I have picked the Rune Hexflash , during the game I realised that but flashed turned grey and couldnt use it for the rest of the game even though it said (READY) while I was pinging it . I logged off and on to see if it fix anything but still nothing . The same thing happended to this guy 2 years ago and still hasn't been patched