Stopping redirect when including wp-load

For some custom code I’m working on, I have to make a page that can be hit by a cron. I made a plugin to handle the front end of the code, and looked at wp-o-matic for thoughts on how to make the cron page. I noticed that it basically requires wp-load at the top of the file and then uses regular wordpress functionality for the rest, which is perfect for my goal. However, when I did the same, my file redirect to the root wp-admin.

Is there some detail I’m missing? How can I get this page to load and do the functionality within without forwarding on to somewhere else?