Bug with Windows 10 console

[akiki@free.fr]

Hi, 
To day, all programs are upgraded permanently. A good and a bad thing.
Windows 10, cygwin ... 
One recent upgrade, I don't target exactly which one, has broken my environment. 


Current versions as reported by cygcheck : 
 Windows 10 Professional Ver 10.0 Build 18363 
 cygwin 3.1.4-1 OK
 bash 4.4.12-3 OK

I am using 2 kinds of console to interact with cygwin
 mintty : using pty as TTY
 bash under cmd : using cons as TTY

These two were working correctly until recently, but now only mintty stay correct.
  -- in reality it's seems
The principal difference is about Ctrl-C interaction.
With the 2nd kind of TTY, a same program using curses, on Ctrl-c
 interrupt the program
 give me a prompt
 but the terminal stay in curses mode, ie without echo and bad new line
I have to do "reset" (/bin/reset) to restore the terminal

So the interrupt handling has changed.
Who is responsible.

I had a look about the new Window Console Legacy.
With this new console, we saw a black screen with color bash prompt.
 
So with bash, is it possible to work with one or other TTY mode ?

Howto understand this problem and what can I do to correct it.
mintty present some problems with my environment and because of that I use the second form of TTY.

Sorry for my bad English.