Redirecting stderr doesn't show the interface

[mattthhh]

Hello, when I try to redirect the stderr of my app as this : ./main.py --debug 2> stderr.dbg the interface doesn't show up. However, i'm pretty sure the program is running because when I hit Ctrl+C the program is being killed or if I hit any other keybindings I binded before, I can see them in my debug file. Any ideas ?