Saving Procedure From Within Experiment

In a certain experiment, when I press command+M (Mac), the "experiment" procedure window pops up with a procedure I've written. I was going to create a new experiment, but wanted to use this up to date procedure. With this procedure as the top window, I click File and looked to save it. The only option is "Save Procedure Copy." So I figure it's saved. I open my new experiment, and go to Recent Files and load the procedure. But it is not the up to date procedure.

I'm confused why, if there are unsaved changes to the procedure, why I was only able to Save Procedure Copy before. If there was a more recent version that I had been saving, I expect that would have been the most recent file.

Is this expected behavior or did I do something funny?
Cmd+M brings up the main procedure window for an experiment. The code in this procedure window is always saved as part of the experiment. In other words, your main procedure window can't be an external procedure (code stored in a file separate from the experiment). Choosing Save Procedure Copy saves the code in a procedure window in a separate ipf file on disk, but that file does not become part of your experiment. If you make changes to the code in an experiment's main procedure window, you must save the experiment itself for those changes to be included when you reopen the experiment.

Since an experiment's main procedure window can't be an external file, you won't see the Save Procedure or Save Procedure As menu items disabled when you have the main procedure window selected.
Execute this:
DisplayHelpTopic "Procedure Windows"
and read about the different types of procedure files.