Hi Tim,
Not sure what the issue is. Here's a small sample app demonstrating setIn working as expected.
Sandbox.json (12.9 KB)
Sandbox | Editor | Retool - 19 February 2024 - Watch Video
Have you tried tying to update action to change rather than using a button? I'm wondering if there's a problem when referring to a separate component rather than using self.value.
Also, have you confirmed that the variable itself is not being updated? There does seem to be a bug in the listView that can prevent it from updating the component state/value even when the underlying data object is updated: New repeatable not loading data when underlying data changes? - #5 by DoingMyBest