[Q] [Neo V]Can't connect via fastboot topic

Hello friends, I have a problem with connect via fastboot on my neo v. It was working, I was flasing with fastboot 2moths ago. Yesterday I try to flash kernel and there were " waiting for device". I run Flashtool, and there I saw " device connected into flash mode" and there is my question... Why? I'm doing flashing too many times on too many phones, my PC have good drivers, also I reinstall it twice and still phone is connecting into flash mode. Ofc blue LED lights. Flash mode is detected on flash mode and fastboot mode. I try to flash kernel via flashify and there is no working, so I try to flash stock rom with flashtool and still I have't fastboot.
Greetings!!