Issue with using hands-free in analog mode

[DiDHack]

I have two MD390G. I have tried to flash one of the first builds and the last firmware. My friend has MD380 and has the same issue. So issue:
If I use a hands-free in the analog mode and press PTT in the hands-free I send silence first 3-5 seconds.
If I use a hands-free in the analog mode and press PTT in the radio it works fine.
If I use a hands-free in the digital mode and press any PTT it works fine.
If I use any stock firmware and a hands-free in any modes and any PTT it works fine.