I know this is an older thread, but I'm having issues with unlocking my S9.. Below is the info. I send the request with just unlock and it says OK, but nothing happens.

Miner Type   Antminer S9
Hostname   antMiner
Model   GNU/Linux
Hardware Version   30.0.1.3
Kernel Version   Linux 3.14.0-xilinx-ga36f3af-dirty #90 SMP PREEMPT Thu Jun 20 15:01:47 CST 2019
File System Version   Tue Jul 30 20:37:39 CST 2019
Logic Version   V1.3.56
BMminer Version   2.0.0
Uptime   1:07
Load Average   0.35, 0.26, 0.29


I noticed the File System version is Jul 30 2019 but firmware is Jun 20th 2019... I've tried every single firmware on Bitmain's website but they have issues flashing due to signature. Thanks for any help!