Welcome to the ZDoom Forums!

I am having some trouble wqith GZDOOM and my XBOX controller. all functionality works perfectly fine EXCEPT after finishing episode 1 m8, I can skip the text and the credits screen appears, but then I cannot do anything. No button on the controller works. The only key on the keyboard that wqorks is "esc" but it is not listed anywhere in the .ini file for key binds so that I can change it to something the controller will recognize. There is no "esc" key as far as the game is concerned and yet it is the only thing that can open the menu on the end episode credits screen.

How can I fix this so that my controller can open the menu to atart the next episode?

You can’t use controller to open main menu from credits screen after episode’s end.
It’s a bug that requires this fix inside the engine.