Cannot enter some mint characters

Question

Using mintty as a terminal, execute it as follows:

C:\cygwin64\bin\mintty.exe -i /Cygwin-Terminal.ico -

I cannot enter characters like ~, [, {...

But I can print all of these characters on the cmd windows terminal and on the default cygwin terminal by running cygwin.bat:

@echo off
C:
chdir C:\cygwin64\bin
bash --login -i

What does mintty do on my keyboard?

* This only happens when remotely uninstalling using Teamviewer *