I have a JS custom include in my form located in the SharePoint SiteAssets library. After I made some edits to the code and saved it, form preview is still executing the old code. When does Nintex reload the files? I've verified my changes have been saved. I also exited the form designer and then reloaded it and still it has the old code. Any ideas?
Depending on your setup, you might need to Publish the file once you have uploaded it to wherever it's living:
If you don't have that option then, yeah, clearning the cache might be the most reliable way to make sure that it's pulling the file fresh from your site.
Have you tried appending versioning to your include URL?
It works for me.