Try to power off and reset your antminer maybe its just glitch or bug .. and try again.. If its not working The other way that i know is firmware corrupted and reflashing firmware would be the solution..But i don't think is it allow to reflash your antminer since its still under warranty.. Better to contact the support from bitmain and ask if it can't avoid your warranty while flashing and ask to guide you.. .
in your opinion, which S9 firmware should I install? There are a lot of options in the Bitmain website and I'm not sure what is the proper one for my device (it's a 14 THs, shipping 11-20 Dec).