Issue with Steamworks Extension

Hello, I'm relatively new to using the Steamworks extension but I've familiarized myself with the extension enough to publish my game onto Steam. However recently I'm now having problems updating my game.

I updated a graphic, and made some code changes to my project.

When I play my game in-engine, I can see this new graphic and the code changes I have made, however, when I create an Executable and play the exe file, all the changes I have made are no longer there and its as if GameMaker is...

Issue with Steamworks Extension