Hey Austin,
That file seems to work for me. The rig is there (but local) and the animation is working and editable.
It might have something to do with how you have linked in the character and created an local copy, rather than an override.
The proxy system has now been sunsetted, and overrides are the way you have to do this now.
Here’s the easiest way in my opinion.
Create your animation file (and save)
Then Link in the character.
Navigate to the master collection (the one in all caps), then click to link it into the file.
Now hit F3 to search and type override, and you will see an option called “override > make”, click that one.
Try “linking” in the character that way rather than clicking the arrow.
