I'm trying to add a modifier to one of my subclasses that's similar to Barbarian Rage damage, just a numeric bonus that increases at certain levels. It's under a Class Feature, and then an Action for that feature. Here's what I've got:

In the Action "Description" box:

"At level {{classlevel}}, your stance bonus is +{{scalevalue}}."

I've tried to set up level overrides like this:

But even though I've added a fixed value there, it's not showing up in the level override table. All you can see there is the level when the override will happen, and the "edit/delete" buttons:

So when I save the feature/subclass and add it to a character sheet, I see this:

 The class feature that this action is part of also has level overrides, and those are working as expected. It's just the action that's misbehaving. Any idea what's causing this?

You are confusing “Scale Value” with “Level Override.” Scale value is not attached to the Action, but to the feature itself in be “At Higher Level Scaling” subform. You need to enter the scale values there. However, you could also accomplish that by means of a snippet calculation as well.

In addition, the {{classlevel}} snippet will always display the PC’s current class level, but that’s kinda redundant and unnecessary in this situation. You could further abridge your snippet to simply read as “Your stance bonus is +{{scalevalue}}."

{{scalevalue}} works in an Action but as IamSposta said, that information is set up in the feature's LEVEL SCALING section. Check this buried comment from the Using Snippet Codes in your Homebrew thread for an exploration of all the snippet codes used in a subclass.

Ah okay, that fixed it! Thanks both of you, and thanks for pointing me to that comment as well, it's very helpful.

Happy to help.